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+id,question,choices,answer
+0,Suppose a file system used only for reading immutable files in random fashion. What is the best block allocation strategy?,"[""Linked-list allocation"", ""Continuous allocation"", ""Index allocation with B-tree"", ""Index allocation with Hash-table""]",B
+1,Suppose a file system used only for reading immutable files in random fashion. What is the best block allocation strategy? Question Options: 1. Linked-list allocation 2. Continuous allocation 3. Index allocation with B-tree 4. Index allocation with Hash-table,"[""Linked-list allocation"", ""Continuous allocation"", ""Index allocation with B-tree"", ""Index allocation with Hash-table""]",B
+2,Which flag prevents user programs from reading and writing kernel data?,"[""PTE_P"", ""PTE_U"", ""PTE_D"", ""PTE_W""]",B
+3,Which of the execution of an application are possible on a single-core machine?,"[""Concurrent execution"", ""Parallel execution"", ""Both concurrent and parallel execution"", ""Neither concurrent or parallel execution""]",A
+4,Which of the execution of an application are possible on a single-core machine? Question Options: 1. Concurrent execution 2. Parallel execution 3. Both concurrent and parallel execution 4. Neither concurrent or parallel execution,"[""Concurrent execution"", ""Parallel execution"", ""Both concurrent and parallel execution"", ""Neither concurrent or parallel execution""]",A
+5,"In JOS, suppose a value is passed between two Envs. What is the minimum number of executed system calls?","[""1"", ""2"", ""3"", ""4""]",B
+6,What strace tool does?,"[""It prints out system calls for given program. These system calls are always called when executing the program."", ""It prints out system calls for given program. These systems calls are called only for that particular instance of the program."", ""To trace a symlink. I.e. to find where the symlink points to."", ""To remove wildcards from the string.""]",B
+7,What is a good distance metric to be used when you want to compute the similarity between documents independent of their length?A penalty will be applied for any incorrect answers.,"[""Cosine similarity"", ""Euclidean distance"", ""Manhattan distance"", ""Chi-squared distance""]",A
+8,Consider a matrix factorization problem of the form $\mathbf{X}=\mathbf{W Z}^{\top}$ to obtain an item-user recommender system where $x_{i j}$ denotes the rating given by $j^{\text {th }}$ user to the $i^{\text {th }}$ item . We use Root mean square error (RMSE) to gauge the quality of the factorization obtained. Select the correct option.,"[""Given a new item and a few ratings from existing users, we need to retrain the already trained recommender system from scratch to generate robust ratings for the user-item pairs containing this item."", ""Regularization terms for $\\mathbf{W}$ and $\\mathbf{Z}$ in the form of their respective Frobenius norms are added to the RMSE so that the resulting objective function becomes convex."", ""For obtaining a robust factorization of a matrix $\\mathbf{X}$ with $D$ rows and $N$ elements where $N \\ll D$, the latent dimension $\\mathrm{K}$ should lie somewhere between $D$ and $N$."", ""None of the other options are correct.""]",D
+9,"You are doing your ML project. It is a regression task under a square loss. Your neighbor uses linear regression and least squares. You are smarter. You are using a neural net with 10 layers and activations functions $f(x)=3 x$. You have a powerful laptop but not a supercomputer. You are betting your neighbor a beer at Satellite who will have a substantially better scores. However, at the end it will essentially be a tie, so we decide to have two beers and both pay. What is the reason for the outcome of this bet?","[""Because we use exactly the same scheme."", ""Because it is almost impossible to train a network with 10 layers without a supercomputer."", ""Because I should have used more layers."", ""Because I should have used only one layer.""]",A
+10,"Let the first four retrieved documents be N N R R, where N denotes a non-relevant and R a relevant document. Then the MAP (Mean Average Precision) is:","[""1/2"", ""5/12"", ""3/4"", ""7/24""]",B
+11,The inverse document frequency of a term can increase,"[""by adding the term to a document that contains the term"", ""by removing a document from the document collection that does not contain the term"", ""by adding a document to the document collection that contains the term"", ""by adding a document to the document collection that does not contain the term""]",D
+12,Which of the following is wrong regarding Ontologies?,"[""We can create more than one ontology that conceptualize the same real-world entities"", ""Ontologies help in the integration of data expressed in different models"", ""Ontologies support domain-specific vocabularies"", ""Ontologies dictate how semi-structured data are serialized""]",D
+13,"In a Ranked Retrieval result, the result at position k is non-relevant and at k+1 is relevant. Which of the following is always true (P@k and R@k are the precision and recall of the result set consisting of the k top ranked documents)?","[""P@k-1 > P@k+1"", ""P@k-1 = P@k+1"", ""R@k-1 < R@k+1"", ""R@k-1 = R@k+1""]",C
+14,What is true regarding Fagin's algorithm?,"[""It performs a complete scan over the posting files"", ""It provably returns the k documents with the largest aggregate scores"", ""Posting files need to be indexed by TF-IDF weights"", ""It never reads more than (kn)½ entries from a posting list""]",B
+15,Which of the following is WRONG for Ontologies?,"[""Different information systems need to agree on the same ontology in order to interoperate."", ""They help in the integration of data expressed in different models."", ""They give the possibility to specify schemas for different domains."", ""They dictate how semi-structured data are serialized.""]",D
+16,Which of the following is WRONG for Ontologies?,"[""Different information systems need to agree on the same ontology in order to interoperate."", ""They help in the integration of data expressed in different models."", ""They give the possibility to specify schemas for different domains."", ""They dictate how semi-structured data are serialized.""]",D
+17,Maintaining the order of document identifiers for vocabulary construction when partitioning the document collection is important,"[""in the index merging approach for single node machines"", ""in the map-reduce approach for parallel clusters"", ""in both"", ""in neither of the two""]",A
+18,Which of the following is correct regarding Crowdsourcing?,"[""Random Spammers give always the same answer for every question"", ""It is applicable only for binary classification problems"", ""Honey Pot discovers all the types of spammers but not the sloppy workers"", ""The output of Majority Decision can be equal to the one of Expectation-Maximization""]",D
+19,"When computing PageRank iteratively, the computation ends when...","[""The difference among the eigenvalues of two subsequent iterations falls below a predefined threshold"", ""The norm of the difference of rank vectors of two subsequent iterations falls below a predefined threshold"", ""All nodes of the graph have been visited at least once"", ""The probability of visiting an unseen node falls below a predefined threshold""]",B
+20,How does LSI querying work?,"[""The query vector is treated as an additional term; then cosine similarity is computed"", ""The query vector is transformed by Matrix S; then cosine similarity is computed"", ""The query vector is treated as an additional document; then cosine similarity is computed"", ""The query vector is multiplied with an orthonormal matrix; then cosine similarity is computed""]",C
+21,Suppose that an item in a leaf node N exists in every path. Which one is correct?,"[""N co-occurs with its prefix in every transaction."", ""For every node P that is a parent of N in the fp tree, confidence(P->N) = 1"", ""N’s minimum possible support is equal to the number of paths."", ""The item N exists in every candidate set.""]",C
+22,"In a Ranked Retrieval result, the result at position k is non-relevant and at k+1 is relevant. Which of the following is always true (P@k and R@k are the precision and recall of the result set consisting of the k top ranked documents)? Question Options: 1. P@k-1 > P@k+1 2. P@k-1 = P@k+1 3. R@k-1 < R@k+ 4. R@k-1 = R@k+1","[""P@k-1 > P@k+1"", ""P@k-1 = P@k+1"", ""R@k-1 < R@k+"", ""R@k-1 = R@k+1""]",C
+23,For the number of times the apriori algorithm and the FPgrowth algorithm for association rule mining are scanning the transaction database the following is true,"[""fpgrowth has always strictly fewer scans than apriori"", ""fpgrowth and apriori can have the same number of scans"", ""apriori cannot have fewer scans than fpgrowth"", ""all three above statements are false""]",B
+24,"Given the following teleporting matrix (Ε) for nodes A, B and C:[0    ½    0][0     0    0][0    ½    1]and making no assumptions about the link matrix (R), which of the following is correct:(Reminder: columns are the probabilities to leave the respective node.)","[""A random walker can never reach node A"", ""A random walker can never leave node A"", ""A random walker can always leave node C"", ""A random walker can always leave node B""]",D
+25,"Given the following teleporting matrix (?) for nodes A, B and C:[0??? ???? 0][0???? 0??? 0][0??? ???? 1]and making no assumptions about the link matrix (R), which of the following is correct:(Reminder: columns are the probabilities to leave the respective node.)","[""A random walker can never reach node A"", ""A random walker can never leave node A"", ""A random walker can always leave node C"", ""A random walker can always leave node B""]",D
+26,"Given the following teleporting matrix (\u0395) for nodes A, B and C:[0  ½  0][0  0  0][0  ½  1]and making no assumptions about the link matrix (R), which of the following is correct:(Reminder: columns are the probabilities to leave the respective node.)","[""A random walker can never reach node A"", ""A random walker can never leave node A"", ""A random walker can always leave node C"", ""A random walker can always leave node B""]",D
+27,"Given the following teleporting matrix (Ε) for nodes A, B and C:[0    ½    0][0     0    0][0    ½    1]and making no assumptions about the link matrix (R), which of the following is correct:(Reminder: columns are the probabilities to leave the respective node.)","[""A random walker can never reach node A"", ""A random walker can never leave node A"", ""A random walker can always leave node C"", ""A random walker can always leave node B""]",D
+28,Which of the following methods does not exploit statistics on the co-occurrence of words in a text?,"[""Word embeddings\n\n\n"", ""Transformers\n\n\n"", ""Vector space retrieval\n\n\n"", ""Fasttext""]",C
+29,Which attribute gives the best split?A1PNa44b44A2PNx51y33A3PNt61j23,"[""A1"", ""A3"", ""A2"", ""All the same""]",B
+30,"Suppose that q is density reachable from p. The chain of points that ensure this relationship are {t,u,g,r} Which one is FALSE?","[""{t,u,g,r} have to be all core points."", ""p and q will also be density-connected"", ""p has to be a core point"", ""q has to be a border point""]",D
+31,The term frequency of a term is normalized,"[""by the maximal frequency of all terms in the document"", ""by the maximal frequency of the term in the document collection"", ""by the maximal frequency of any term in the vocabulary"", ""by the maximal term frequency of any document in the collection""]",A
+32,"When compressing the adjacency list of a given URL, a reference list","[""Is chosen from neighboring URLs that can be reached in a small number of hops"", ""May contain URLs not occurring in the adjacency list of the given URL"", ""Lists all URLs not contained in the adjacency list of given URL"", ""All of the above""]",B
+33,Data being classified as unstructured or structured depends on the:,"[""Degree of abstraction"", ""Level of human involvement"", ""Type of physical storage"", ""Amount of data ""]",A
+34,Data being classified as unstructured or structured depends on the: Question Options: 1. Degree of abstraction 2. Level of human involvement 3. Type of physical storage 4. Amount of data,"[""Degree of abstraction"", ""Level of human involvement"", ""Type of physical storage"", ""Amount of data ""]",A
+35,"Suppose you have a search engine that retrieves the top 100 documents and achieves 90% precision and 20% recall. You modify the search engine to retrieve the top 200 and mysteriously, the precision stays the same. Which one is CORRECT?","[""The recall becomes 10%"", ""The number of relevant documents is 450"", ""The F-score stays the same"", ""This is not possible""]",B
+36,"In the χ2 statistics for a binary feature, we obtain P(χ2 | DF = 1) > 0.05. This means in this case, it is assumed:","[""That the class labels depends on the feature"", ""That the class label is independent of the feature"", ""That the class label correlates with the feature"", ""None of the above""]",B
+37,Which of the following is correct regarding the use of Hidden Markov Models (HMMs) for entity recognition in text documents? Question Options: 1. The cost of learning the model is quadratic in the lengths of the text. 2. The cost of predicting a word is linear in the lengths of the text preceding the word. 3. An HMM model can be built using words enhanced with morphological features as input. 4. The label of one word is predicted based on all the previous labels,"[""The cost of learning the model is quadratic in the lengths of the text."", ""The cost of predicting a word is linear in the lengths of the text preceding the word."", ""An HMM model can be built using words enhanced with morphological features as input."", ""The label of one word is predicted based on all the previous labels""]",C
+38,Which of the following is correct regarding the use of Hidden Markov Models (HMMs) for entity recognition in text documents?,"[""The cost of learning the model is quadratic in the lengths of the text."", ""The cost of predicting a word is linear in the lengths of the text preceding the word."", ""An HMM model can be built using words enhanced with morphological features as input."", ""The label of one word is predicted based on all the previous labels""]",C
+39,"10 itemsets out of 100 contain item A, of which 5 also contain B. The rule A -> B has:","[""5% support and 10% confidence"", ""10% support and 50% confidence"", ""5% support and 50% confidence"", ""10% support and 10% confidence""]",C
+40,A basic statement in RDF would be expressed in the relational data model by a table,"[""with one attribute"", ""with two attributes"", ""with three attributes"", ""cannot be expressed in the relational data model""]",B
+41,Which of the following statements is wrong regarding RDF?,"[""An RDF statement would be expressed in SQL as a tuple in a table"", ""Blank nodes in RDF graphs correspond to the special value NULL in SQL"", ""The object value of a type statement corresponds to a table name in SQL"", ""RDF graphs can be encoded as SQL databases""]",B
+42,The number of non-zero entries in a column of a term-document matrix indicates:,"[""how many terms of the vocabulary a document contains"", ""how often a term of the vocabulary occurs in a document"", ""how relevant a term is for a document "", ""none of the other responses is correct""]",A
+43,A false negative in sampling can only occur for itemsets with support smaller than,"[""the threshold s"", ""p*s"", ""p*m"", ""None of the above""]",D
+44,Why is XML a document model?,"[""It supports application-specific markup"", ""It supports domain-specific schemas"", ""It has a serialized representation"", ""It uses HTML tags""]",C
+45,A retrieval model attempts to capture,"[""the interface by which a user is accessing information"", ""the importance a user gives to a piece of information for a query"", ""the formal correctness of a query formulation by user"", ""the structure by which a document is organised""]",B
+46,"When computing HITS, the initial values","[""Are set all to 1"", ""Are set all to 1/n"", ""Are set all to 1/sqrt(n)"", ""Are chosen randomly""]",C
+47,"When indexing a document collection using an inverted file, the main space requirement is implied by","[""The access structure"", ""The vocabulary"", ""The index file"", ""The postings file""]",D
+48,Which statement is correct?,"[""The Viterbi algorithm works because words are independent in a sentence"", ""The Viterbi algorithm works because it is applied to an HMM model that makes an independence assumption on the word dependencies in sentences"", ""The Viterbi algorithm works because it makes an independence assumption on the word dependencies in sentences"", ""The Viterbi algorithm works because it is applied to an HMM model that captures independence of words in a sentence""]",B
+49,"Which of the following is WRONG about inverted files? (Slide 24,28 Week 3)","[""The space requirement for the postings file is O(n)"", ""Variable length compression is used to reduce the size of the index file"", ""The index file has space requirement of O(n^beta), where beta is about 1⁄2"", ""Storing differences among word addresses reduces the size of the postings file""]",B
+50,Which of the following is WRONG about inverted files?,"[""The space requirement for the postings file is O(n)"", ""Variable length compression is used to reduce the size of the index file"", ""The index file has space requirement of O(n^beta), where beta is about 1⁄2"", ""Storing differences among word addresses reduces the size of the postings file""]",B
+51,"In User-Based Collaborative Filtering, which of the following is TRUE?","[""Pearson Correlation Coefficient and Cosine Similarity have the same value range and return the same similarity ranking for the users."", ""Pearson Correlation Coefficient and Cosine Similarity have different value ranges and can return different similarity rankings for the users"", ""Pearson Correlation Coefficient and Cosine Similarity have different value ranges, but return the same similarity ranking for the users"", ""Pearson Correlation Coefficient and Cosine Similarity have the same value range but can return different similarity rankings for the users""]",B
+52,Which of the following is TRUE for Recommender Systems (RS)?,"[""The complexity of the Content-based RS depends on the number of users"", ""Item-based RS need not only the ratings but also the item features"", ""Matrix Factorization is typically robust to the cold-start problem."", ""Matrix Factorization can predict a score for any user-item combination in the dataset.""]",D
+53,"When using bootstrapping in Random Forests, the number of different data items used to construct a single tree is:","[""Smaller than the size of the training data set with high probability"", ""Of order square root of the size of the training set with high probability"", ""The same as the size of the training data set"", ""Depends on the outcome of the sampling process, and can be both smaller or larger than the training set""]",A
+54,"To constrain an object of an RDF statement from being of an atomic type (e.g., String), one has to use the following RDF/RDFS property:","[""rdf:type"", ""rdfs:range"", ""rdfs:domain"", ""rdfs:subClassOf""]",B
+55,What is a correct pruning strategy for decision tree induction?,"[""Apply Maximum Description Length principle"", ""Stop partitioning a node when either positive or negative samples dominate the samples of the other class"", ""Choose the model that maximizes L(M) + L(M|D)"", ""Remove attributes with lowest information gain""]",B
+56,In the first pass over the database of the FP Growth algorithm,"[""Frequent itemsets are extracted"", ""A tree structure is constructed"", ""The frequency of items is computed"", ""Prefixes among itemsets are determined""]",C
+57,"Your input is ""Distributed Information Systems"". Your model tries to predict ""Distributed"" and ""Systems"" by leveraging the fact that these words are in the neighborhood of ""Information"". This model can be:","[""Bag of Words"", ""Word Embeddings"", ""LDA"", ""kNN""]",B
+58,"Considering the transaction below, which one is WRONG?  |Transaction ID |Items Bought| |--|--| |1|Tea| |2|Tea, Yoghurt| |3|Tea, Yoghurt, Kebap| |4 |Kebap | |5|Tea, Kebap|","[""{Yoghurt} -> {Kebab} has 50% confidence"", ""{Yoghurt, Kebap} has 20% support"", ""{Tea} has the highest support"", ""{Yoghurt} has the lowest support among all itemsets""]",D
+59,Which is an appropriate method for fighting skewed distributions of class labels in classification?,"[""Include an over-proportional number of samples from the larger class"", ""Use leave-one-out cross validation"", ""Construct the validation set such that the class label distribution approximately matches the global distribution of the class labels"", ""Generate artificial data points for the most frequent classes""]",C
+60,Which of the following is true in the context of inverted files?,"[""Index merging compresses an inverted file index on disk and reduces the storage cost"", ""The trie structure used for index construction is also used as a data access structure to terms in the vocabulary"", ""The finer the addressing granularity used in documents, the smaller the posting file becomes"", ""Inverted files are optimized for supporting search on dynamic text collections""]",B
+61,The type statement in RDF would be expressed in the relational data model by a table,"[""with one attribute"", ""with two attributes"", ""with three attributes"", ""cannot be expressed in the relational data model""]",A
+62,"Given graph 1→2, 1→3, 2→3, 3→2, switching from Page Rank to Teleporting PageRank will have an influence on the value(s) of: Question Options: 1. All the nodes 2. Node 1 3. Node 2 and 3 4. No nodes. The values will stay unchanged.","[""All the nodes"", ""Node 1"", ""Node 2 and 3"", ""No nodes. The values will stay unchanged.""]",A
+63,"Given graph 1→2, 1→3, 2→3, 3→2, switching from Page Rank to Teleporting PageRank will have an influence on the value(s) of:","[""All the nodes"", ""Node 1"", ""Node 2 and 3"", ""No nodes. The values will stay unchanged.""]",A
+64,"Given graph 1→2, 1→3, 2→3, 3→2, switching from Page Rank to Teleporting PageRank will have an influence on the value(s) of:","[""All the nodes"", ""Node 1"", ""Node 2 and 3"", ""No nodes. The values will stay unchanged.""]",A
+65,Which of the following is true regarding the random forest classification algorithm?,"[""It is not suitable for parallelization."", ""It uses only a subset of features for learning in each weak learner."", ""We compute a prediction by randomly selecting the decision of one weak learner."", ""It produces a human interpretable model.""]",B
+66,How does matrix factorization address the issue of missing ratings?,"[""It uses regularization of the rating matrix"", ""It performs gradient descent only for existing ratings"", ""It sets missing ratings to zero"", ""It maps ratings into a lower-dimensional space""]",B
+67,"When constructing a word embedding, negative samples are","[""word - context word combinations that are not occurring in the document collection"", ""context words that are not part of the vocabulary of the document collection"", ""all less frequent words that do not occur in the context of a given word"", ""only words that never appear as context word""]",A
+68,Which of the following tasks would typically not be solved by clustering?,"[""Community detection in social networks"", ""Discretization of continuous features"", ""Spam detection in an email system"", ""Detection of latent topics in a document collection""]",C
+69,"In general, what is true regarding Fagin's algorithm?","[""It performs a complete scan over the posting files"", ""It provably returns the k documents with the largest aggregate scores"", ""Posting files need to be indexed by the TF-IDF weights"", ""It never reads more than (kn)½ entries from a posting list""]",B
+70,Which of the following statements is correct in the context of  information extraction?,"[""A confidence measure that prunes too permissive patterns discovered with bootstrapping can help reducing semantic drift"", ""The bootstrapping technique requires a dataset where statements are labelled"", ""Distant supervision typically uses low-complexity features only, due to the lack of training data"", ""For supervised learning, sentences in which NER has detected no entities are used as negative samples""]",A
+71,Which of the following statements is correct in the context of  information extraction?,"[""A confidence measure that prunes too permissive patterns discovered with bootstrapping can help reducing semantic drift"", ""The bootstrapping technique requires a dataset where statements are labelled"", ""Distant supervision typically uses low-complexity features only, due to the lack of training data"", ""For supervised learning, sentences in which NER has detected no entities are used as negative samples""]",A
+72,In vector space retrieval each row of the matrix M corresponds to,"[""A document"", ""A concept"", ""A query"", ""A term""]",D
+73,Applying SVD to a term-document matrix M. Each concept is represented in K,"[""as a singular value"", ""as a linear combination of terms of the vocabulary"", ""as a linear combination of documents in the document collection"", ""as a least squares approximation of the matrix M""]",B
+74,An HMM model would not be an appropriate approach to identify,"[""Named Entities"", ""Part-of-Speech tags"", ""Concepts"", ""Word n-grams""]",D
+75,Which of the following is NOT an (instance-level) ontology?,"[""Wordnet"", ""WikiData"", ""Schema.org"", ""Google Knowledge Graph""]",C
+76,What is our final goal in machine learning? (One answer),"["" Generalize "", "" Underfit"", "" Overfit "", "" Megafit ""]",A
+77,"A model predicts $\mathbf{\hat{y}} = [1, 0, 1, 1, 1]$. The ground truths are $\mathbf{y} = [1, 0, 0, 1, 1]$.  What is the accuracy?","[""0.5"", ""0.75"", ""0.8"", ""0.875""]",C
+78,You write a Python code to optimize the weights of your linear regression with 10 features \textbf{using gradient descent} for 500 epochs. What is the minimum number of for-loops you need to perform your optimization?,"[""Two for-loops, one to iterate over the weights and the other to iterate over the epochs"", ""Only one for-loop to iterate over the epochs."", ""Only one for-loop to iterate over the weights."", ""No for-loop is really necessary. Everything can be vectorized""]",B
+79,Fill the missing line of code: (one answer)\\  \hspace*{.5cm} \#code missing\\  \hspace*{.5cm} np.mean(np.random.randn(1000))\\ Question Options: 1. import np 2. import numpy 3. import numpy as np 4. import np.mean\\ 		import np.random,"[""import np"", ""import numpy"", ""import numpy as np"", ""import np.mean\\\\\n\t\timport np.random""]",C
+80,Fill the missing line of code: (one answer)\\  \hspace*{.5cm} \#code missing\\  \hspace*{.5cm} np.mean(np.random.randn(1000))\\,"[""import np"", ""import numpy"", ""import numpy as np"", ""import np.mean\\\\\n\t\timport np.random""]",C
+81,What is the output of the following block of Python code? (one answer) \\ \verb|my_string = `computational'| \\ \verb|print(my_string[1])|\\ \verb|print(my_string[3:5])| \vspace{0.25cm},"[""c\\\\mpu"", ""c\\\\mp"", ""o\\\\put"", ""o\\\\pu""]",D
+82,"You are using a 3-layer fully-connected neural net with \textbf{ReLU activations}. Your input data has components in [0, 1]. \textbf{You initialize all your weights to -10}, and set all the bias terms to 0. You start optimizing using SGD. What will likely happen?","[""The gradient is 0 so nothing happens"", ""The gradient is very large so the model can't converge"", ""Training is fine, but our neural net does only as well as a linear model"", ""Everything is fine""]",A
+83,Mean Square Error loss:,"[""Minimizing the distance between the predicted point and the true point"", ""Maximizing the probability of the correct class"", ""Minimizing the score of false classes when they are close, or bigger than, the score of the true class"", ""Maximizing the accuracy""]",A
+84,"Mean Square Error loss: Question Options: 1. Minimizing the distance between the predicted point and the true point 2. Maximizing the probability of the correct class 3. Minimizing the score of false classes when they are close, or bigger than, the score of the true class 4. Maximizing the accuracy","[""Minimizing the distance between the predicted point and the true point"", ""Maximizing the probability of the correct class"", ""Minimizing the score of false classes when they are close, or bigger than, the score of the true class"", ""Maximizing the accuracy""]",A
+85,"Consider the following PyTorch code:      class ThreeLayerNet (nn.Module):         def __init__():             super().__init__()                  def forward(x):             x = nn.Linear(100, 10)(x)             x = nn.ReLU()(x)             x = nn.Linear(10, 200)(x)             x = nn.ReLU()(x)             x = nn.Linear(200, 1)(x)             return x       Suppose that inputs are 100-dimensional, and outputs are 1-dimensional. What will happen if we try to train this network?","[""There will be an error because we are re-using the variable x throughout the forward() method."", ""There will be an error because the second layer has more neurons than the first. The number of neurons must never increase from one layer to the next."", ""The model will not train properly. The performance will be the same at the beginning of the first epoch and at the end of the last epoch."", ""Everything is fine.""]",C
+86,"You are using a 3-layer fully-connected neural net with \textbf{ReLU activations}. Your input data has components in [0, 1]. \textbf{You initialize your weights by sampling from $\mathcal{N}(-10, 0.1)$ (Gaussians of mean -10 and variance 0.1)}, and set all the bias terms to 0. You start optimizing using SGD. What will likely happen?","[""The gradient is 0 so nothing happens"", ""The gradient is very large so the model can't converge"", ""Training is fine, but our neural net does only as well as a linear model"", ""Everything is fine""]",A
+87,The \textbf{parameters} (weights \textbf{W}) are learned with ... (One answer),"["" training "", ""  validation "", "" test "", "" all the data together ""]",A
+88,The \textbf{hyperparameters} are learned with ... (One answer),"["" training "", ""  validation "", "" test "", "" all the data together ""]",B
+89,"We report the final performance (e.g., accuracy) on the ... (One answer)","["" training "", ""  validation "", "" test "", "" all the data together ""]",C
+90,Consider the function $f(x)=-x^{2}$. Which of the following statements are true regarding subgradients of $f(x)$ at $x=0$ ?,"[""A subgradient does not exist as $f(x)$ is differentiable at $x=0$."", ""A subgradient exists but is not unique."", ""A subgradient exists and is unique."", ""A subgradient does not exist even though $f(x)$ is differentiable at $x=0$.""]",D
+91,"When constructing a word embedding, what is true regarding negative samples?","[""They are words that do not appear as context words"", ""They are selected among words which are not stop words"", ""Their frequency is decreased down to its logarithm"", ""They are oversampled if less frequent""]",D
+92,If the top 100 documents contain 50 relevant documents,"[""the precision of the system at 50 is 0.25"", ""the precision of the system at 100 is 0.5"", ""the recall of the system is 0.5"", ""All of the above""]",B
+93,What is WRONG regarding the Transformer model?,"[""It uses a self-attention mechanism to compute representations of the input and output."", ""Its computation cannot be parallelized compared to LSTMs and other sequential models."", ""Its complexity is quadratic to the input size."", ""It captures the semantic context of the input.""]",B
+94,"Suppose that in a given FP Tree, an item in a leaf node N exists in every path. Which of the following is true?","[""N co-occurs with its prefixes in every transaction"", ""{N}’s minimum possible support is equal to the number of paths"", ""For every node P that is a parent of N in the FP tree, confidence(P->N) = 1"", ""The item N exists in every candidate set""]",B
+95,Modularity of a social network always:,"[""Increases with the number of communities"", ""Increases when an edge is added between two members of the same community"", ""Decreases when new nodes are added to the social network that form their own communities"", ""Decreases if an edge is removed""]",B
+96,Which of the following statements is correct concerning the use of Pearson’s Correlation for user- based collaborative filtering?,"[""It measures whether different users have similar preferences for the same items"", ""It measures how much a user’s ratings deviate from the average ratings I"", ""t measures how well the recommendations match the user’s preferences"", ""It measures whether a user has similar preferences for different items""]",A
+97,Which of the following statements is correct concerning the use of Pearson’s Correlation for user- based collaborative filtering?,"[""It measures whether different users have similar preferences for the same items"", ""It measures how much a user’s ratings deviate from the average ratings I"", ""t measures how well the recommendations match the user’s preferences"", ""It measures whether a user has similar preferences for different items""]",A
+98,Which is true about the use of entropy in decision tree induction?,"[""The entropy of the set of class labels of the samples from the training set at the leaf level is always 0"", ""We split on the attribute that has the highest entropy"", ""The entropy of the set of class labels of the samples from the training set at the leaf level can be 1"", ""We split on the attribute that has the lowest entropy""]",C
+99,Modularity clustering will end up always with the same community structure?,"[""True"", ""Only for connected graphs"", ""Only for cliques"", ""False""]",D
+100,Which of the following graph analysis techniques do you believe would be most appropriate to identify communities on a social graph?,"[""Cliques"", ""Random Walks"", ""Shortest Paths"", ""Association rules""]",A
+101,Which of the following models for generating vector representations for text require to precompute the frequency of co-occurrence of words from the vocabulary in the document collection,"[""LSI"", ""CBOW"", ""Fasttext"", ""Glove""]",D
+102,For which document classifier the training cost is low and inference is expensive?,"[""for none"", ""for kNN"", ""for NB"", ""for fasttext""]",B
+103,"In Ranked Retrieval, the result at position k is non-relevant and at k+1 is relevant. Which of the following is always true? Hint: P@k and R@k are the precision and recall of the result set consisting of the k top-ranked documents.","[""P@k-1>P@k+1"", ""R@k-1=R@k+1"", ""R@k-1<R@k+1"", ""P@k-1=P@k+1""]",C
+104,"Regarding the Expectation-Maximization algorithm, which one of the following false?","[""Assigning equal weights to workers initially decreases the convergence time"", ""The label with the highest probability is assigned as the new label"", ""It distinguishes experts from normal workers"", ""In E step the labels change, in M step the weights of the workers change""]",A
+105,"For an item that has not received any ratings, which method can make a prediction?","[""User-based collaborative RS"", ""Item-based collaborative RS"", ""Content-based RS"", ""None of the above""]",C
+106,The SMART algorithm for query relevance feedback modifies? (Slide 11 Week 3),"[""The original document weight vectors"", ""The original query weight vectors"", ""The result document weight vectors"", ""The keywords of the original user query""]",B
+107,"In Ranked Retrieval, the result at position k is non-relevant and at k+1 is relevant. Which of the following is always true?Hint: P@k and R@k are the precision and recall of the result set consisting of the k top ranked documents.","[""P@k-1>P@k+1"", ""P@k-1=P@k+1"", ""R@k-1<R@k+1"", ""R@k-1=R@k+1""]",C
+108,"Suppose that for points p, q, and t in metric space, the following hold:p is density-reachable from q t is density-reachable from qp is density-reachable from tWhich of the following statements is false?","[""t is a core point"", ""p is a border point"", ""p and q are density-connected"", ""q is a core point ""]",B
+109,"Suppose that for points p, q, and t in metric space, the following hold:p is density-reachable from q t is density-reachable from qp is density-reachable from tWhich of the following statements is false?","[""t is a core point"", ""p is a border point"", ""p and q are density-connected"", ""q is a core point ""]",B
+110,"If for the χ2 statistics for a binary feature, we obtain P(χ2 |DF = 1) < 0.05, this means:","[""That the class labels depends on the feature"", ""That the class label is independent of the feature"", ""That the class label correlates with the feature"", ""No conclusion can be drawn""]",A
+111,"If for the χ2 statistics for a binary feature, we obtain P(χ2 |DF = 1) < 0.05, this means:","[""That the class labels depends on the feature"", ""That the class label is independent of the feature"", ""That the class label correlates with the feature"", ""No conclusion can be drawn""]",A
+112,"When constructing a word embedding, negative samples are: Question Options: 1. Word - context word combinations that are not occurring in the document collection 2. Context words that are not part of the vocabulary of the document collection 3. All less frequent words that do not occur in the context of a given word 4. Only words that never appear as context word","[""Word - context word combinations that are not occurring in the document collection"", ""Context words that are not part of the vocabulary of the document collection"", ""All less frequent words that do not occur in the context of a given word"", ""Only words that never appear as context word""]",A
+113,"When constructing a word embedding, negative samples are:","[""Word - context word combinations that are not occurring in the document collection"", ""Context words that are not part of the vocabulary of the document collection"", ""All less frequent words that do not occur in the context of a given word"", ""Only words that never appear as context word""]",A
+114,"Let $f_{\mathrm{MLP}}: \mathbb{R}^{d} \rightarrow \mathbb{R}$ be an $L$-hidden layer multi-layer perceptron (MLP) such that $$ f_{\mathrm{MLP}}(\mathbf{x})=\mathbf{w}^{\top} \sigma\left(\mathbf{W}_{L} \sigma\left(\mathbf{W}_{L-1} \ldots \sigma\left(\mathbf{W}_{1} \mathbf{x}\right)\right)\right) $$ with $\mathbf{w} \in \mathbb{R}^{M}, \mathbf{W}_{1} \in \mathbb{R}^{M \times d}$ and $\mathbf{W}_{\ell} \in \mathbb{R}^{M \times M}$ for $\ell=2, \ldots, L$, and $\sigma$ is an entry-wise activation function. Also, let $f_{\mathrm{CNN}}: \mathbb{R}^{d} \rightarrow \mathbb{R}$ be an $L^{\prime}$-hidden layer convolutional neural network (CNN) such that $$ f_{\mathrm{CNN}}(\mathbf{x})=\mathbf{w}^{\top} \sigma\left(\mathbf{w}_{L^{\prime}} \star \sigma\left(\mathbf{w}_{L^{\prime}-1} \star \ldots \sigma\left(\mathbf{w}_{1} \star \mathbf{x}\right)\right)\right) $$ with $\mathbf{w} \in \mathbb{R}^{d}, \mathbf{w}_{\ell} \in \mathbb{R}^{K}$ for $\ell=1, \ldots, L^{\prime}$ and $\star$ denoting the one-dimensional convolution operator with zero-padding, i.e., output of the convolution has the same dimensionality as the input. Let's assume $\sigma$ is a tanh activation function. Thus, by flipping the signs of all of the weights leading in and out of a hidden neuron, the input-output mapping function represented by the network is unchanged. Besides, interchanging the values of all of the weights (i.e., by permuting the ordering of the hidden neurons within the layer) also leaves the network input-output mapping function unchanged. Suppose that, given the training data, SGD can find a solution with zero training loss, and the (absolute value) weights of such solution are non-zero and all unique. Choose the largest lower bound on the number of solutions (with zero training loss) achievable by $f_{\mathrm{MLP}}$ with $L=1$ and $M$ hidden units on this dataset.","[""$M! 2^M$"", ""$1$"", ""$2^M$"", ""$M !$""]",A
+115,"Consider a linear regression problem with $N$ samples $\left\{\left(\boldsymbol{x}_{n}, y_{n}\right)\right\}_{n=1}^{N}$, where each input $\boldsymbol{x}_{n}$ is a $D$-dimensional vector $\{-1,+1\}^{D}$, and all output values are $y_{i} \in \mathbb{R}$. Which of the following statements is correct?","[""Linear regression always \""works\"" very well for $N \\ll D$"", ""A linear regressor works very well if the data is linearly separable."", ""Linear regression always \""works\"" very well for $D \\ll N$"", ""None of the above.""]",D
+116,"You are given two distributions over $\mathbb{R}$ : Uniform on the interval $[a, b]$ and Gaussian with mean $\mu$ and variance $\sigma^{2}$. Their respective probability density functions are $$ p_{\mathcal{U}}(y \mid a, b):=\left\{\begin{array}{ll} \frac{1}{b-a}, & \text { for } a \leq y \leq b, \\ 0 & \text { otherwise } \end{array} \quad p_{\mathcal{G}}\left(y \mid \mu, \sigma^{2}\right):=\frac{1}{\sqrt{2 \pi \sigma^{2}}} \exp \left(-\frac{(y-\mu)^{2}}{2 \sigma^{2}}\right)\right. $$ Which one(s) belong to the exponential family?","[""Only Uniform."", ""Both of them."", ""Only Gaussian."", ""None of them.""]",C
+117,Church booleans are a representation of booleans in the lambda calculus. The Church encoding of true and false are functions of two parameters: Church encoding of tru: t => f => t Church encoding of fls: t => f => f What should replace ??? so that the following function computes not(b and c)? b => c => b ??? (not b),"[""(not b)"", ""(not c)"", ""tru"", ""fls""]",B
+118,To which expression is the following for-loop translated? for x <- xs if x > 5; y <- ys yield x + y,"[""xs.flatMap(x => ys.map(y => x + y)).withFilter(x => x > 5)"", ""xs.withFilter(x => x > 5).map(x => ys.flatMap(y => x + y))"", ""xs.withFilter(x => x > 5).flatMap(x => ys.map(y => x + y))"", ""xs.map(x => ys.flatMap(y => x + y)).withFilter(x => x > 5)""]",C
+119,"A query \(q\) has been submitted to two distinct Information Retrieval engines operating on the same document collection containing 1'000 documents, with 50 documents being truly relevant for \(q\).The following result lists have been produced by the two IR engines, \(S_1\) and \(S_2\) respectively:  \(S_1\text{:}\) \(d_1\) \(d_2\text{ (*)}\) \(d_3\text{ (*)}\) \(d_4\) \(d_5\text{ (*)}\)  \(S_2\text{:}\) \(d^\prime_1\text{ (*)}\) \(d^\prime_2\text{ (*)}\) \(d^\prime_3\) \(d^\prime_4\) \(d^\prime_5\)  In these result lists, the stars \(\text{(*)}\) identify the truly relevant documents. By convention, we consider that any non retrieved document has been retrieved at rank 6.If Average Precision is used as evaluation metric, which of the two IR engines is performing better for the query \(q\)?","[""\\(S_1\\)"", ""\\(S_2\\)"", ""Both engines perform equally."", ""This evaluation metric cannot be computed.""]",B
+120,"A multiset is an unordered collection where elements can appear multiple times. We will represent a multiset of Char elements as a function from Char to Int: the function returns 0 for any Char argument that is not in the multiset, and the (positive) number of times it appears otherwise: type Multiset = Char => Int The filter operation on a multiset m returns the subset of m for which p holds. What should replace ??? so that the filter function is correct? def filter(m: Multiset, p: Char => Boolean): Multiset = ???","[""x => if m(x) then p(x) else 0"", ""x => m(x) && p(x)"", ""x => if !m(x) then p(x) else 0"", ""x => if p(x) then m(x) else 0""]",D
+121,Tick the \textbf{true} assertion. Let $X$ be a random variable defined by the visible face showing up when throwing a dice. Its expected value $E(X)$ is:,"[""3.5"", ""3"", ""1"", ""4""]",C
+122,"In x86-64 Linux, the canary is \textbf{always} different for every?","[""Thread"", ""Function"", ""Process"", ""Namespace""]",A
+123,"You share an apartment with friends. Kitchen, living room, balcony, and bath room are shared resources among all parties. Which policy/policies violate(s) the principle of least privilege?","[""Different bedrooms do not have a different key."", ""There is no lock on the fridge."", ""To access the kitchen you have to go through the living room."", ""Nobody has access to the neighbor's basement.""]",A
+124,"Consider the Diffie-Hellman secret-key-exchange algorithm performed in the cyclic group $(\mathbb{Z}/11\mathbb{Z}^\star, \cdot)$. Let $g=2$ be the chosen group generator. Suppose that Alice's secret number is $a=5$ and Bob's is $b=3$. Which common key $k$ does the algorithm lead to? Check the correct answer.","[""$10$"", ""$7$"", ""$8$"", ""$9$""]",A
+125,How many integers $n$ between $1$ and $2021$ satisfy $10^n \equiv 1 \mod 11$? Check the correct answer.,"[""1010"", ""183"", ""505"", ""990""]",A
+126,"You are given an i.i.d source with symbols taking value in the alphabet $\mathcal{A}=\{a,b,c,d\}$ and probabilities $\{1/8,1/8,1/4,1/2\}$. Consider making blocks of length $n$ and constructing a Huffman code that assigns a binary codeword to each block of $n$ symbols. Choose the correct statement regarding the average codeword length per source symbol.","[""It is the same for all $n$."", ""It strictly decreases as $n$ increases."", ""None of the others."", ""In going from $n$ to $n+1$, for some $n$ it stays constant and for some it strictly decreases.""]",A
+127,A bag contains the letters of LETSPLAY. Someone picks at random 4 letters from the  bag without revealing the outcome to you. Subsequently you pick one letter at random among the remaining 4 letters. What is the entropy (in bits) of the random variable that models your choice? Check the correct answer.,"[""$\frac{11}{4}$"", ""$2$"", ""$\\log_2(7)$"", ""$\\log_2(8)$""]",A
+128,"Consider the group $(\mathbb{Z} / 23 \mathbb{Z}^*, \cdot)$. Find how many elements of the group are generators of the group. (Hint: $5$ is a generator of the group.)","[""$10$"", ""$22$"", ""$11$"", ""$2$""]",A
+129,"In RSA, we set $p = 7, q = 11, e = 13$. The public key is $(m, e) = (77, 13)$. The ciphertext we receive is $c = 14$. What is the message that was sent? (Hint: You may solve faster using Chinese remainder theorem.).","[""$t=42$"", ""$t=14$"", ""$t=63$"", ""$t=7$""]",A
+130,"Consider an RSA encryption where the public key is published as $(m, e) = (35, 11)$. Which one of the following numbers is a valid decoding exponent?","[""$11$"", ""$7$"", ""$5$"", ""$17$""]",A
+131,"Let $\mathcal{C}$ be a binary $(n,k)$ linear code with minimum distance $d_{\min} = 4$. Let $\mathcal{C}'$ be the code obtained by adding a parity-check bit $x_{n+1}=x_1 \oplus x_2 \oplus \cdots \oplus x_n$ at the end of each codeword of $\mathcal{C}$. Let $d_{\min}'$ be the minimum distance of $\mathcal{C}'$. Which of the following is true?","[""$d_{\\min}' = 4$"", ""$d_{\\min}' = 5$"", ""$d_{\\min}' = 6$"", ""$d_{\\min}'$ can take different values depending on the code $\\mathcal{C}$.""]",A
+132,"Let $\mathcal{C}$ be a $(n,k)$ Reed-Solomon code on $\mathbb{F}_q$. Let $\mathcal{C}'$ be the $(2n,k)$ code such that each codeword of $\mathcal{C}'$ is a codeword of $\mathcal{C}$ repeated twice, i.e., if $(x_1,\dots,x_n) \in\mathcal{C}$, then $(x_1,\dots,x_n,x_1,\dots,x_n)\in\mathcal{C'}$. What is the minimum distance of $\mathcal{C}'$?","[""$2n-2k+2$"", ""$2n-k+1$"", ""$2n-2k+1$"", ""$2n-k+2$""]",A
+133,"Let $\mathcal{C}$ be a $(n,k)$ Reed-Solomon code ... What is the minimum distance of $\mathcal{C}'$?","[""$2n-2k+2$"", ""$2n-k+1$"", ""$2n-2k+1$"", ""$2n-k+2$""]",A
+134,"Consider the following mysterious binary encoding:egin{center}    egin{tabular}{c|c}     symbol & encoding \     \hline      $a$ & $??0$\      $b$ & $??0$\      $c$ & $??0$\      $d$ & $??0$ \end{tabular} \end{center} where with '$?$' we mean that we do not know which bit is assigned as the first two symbols of the encoding of any of the source symbols $a,b,c,d$. What can you infer on this encoding assuming that the code-words are all different?","[""The encoding is uniquely-decodable."", ""The encoding is uniquely-decodable but not prefix-free."", ""We do not possess enough information to say something about the code."", ""It does not satisfy Kraft's Inequality.""]",A
+135,"A colleague challenges you to create a $(n-1,k,d_{min})$ code $\mathcal C'$ from a $(n,k,d_{min})$ code $\mathcal C$ as follows: given a generator matrix $G$ that generates $\mathcal C$, drop one column from $G$. Then, generate the new code with this truncated $k 	imes (n-1)$ generator matrix. The catch is that your colleague only gives you a set $\mathcal S=\{\vec s_1,\vec s_2, \vec s_3\}$ of $3$ columns of $G$ that you are allowed to drop, where $\vec s_1$ is the all-zeros vector, $\vec s_2$ is the all-ones vector, and $\vec s_3$ is a canonical basis vector. From the length of the columns $s_i$ you can infer $k$. You do not know $n$, neither do you know anything about the $n-3$ columns of $G$ that are not in $\mathcal S$. However, your colleague tells you that $G$ is in systematic form, i.e., $G=[I ~~ P]$ for some unknown $P$, and that all of the elements in $\mathcal S$ are columns of $P$. Which of the following options in $\mathcal S$ would you choose as the column of $G$ to drop?","[""$\\vec s_1$ (the all-zeros vector)."", ""$\\vec s_2$ (the all-ones vector)"", ""$\\vec s_3$ (one of the canonical basis vectors)."", ""It is impossible to guarantee that dropping a column from $\\mathcal S$ will not decrease the minimum distance.""]",A
+136,"A binary prefix-free code $\Gamma$ is made of four codewords. The first three codewords have codeword lengths $\ell_1 = 2$, $\ell_2 = 3$ and $\ell_3 = 3$. What is the minimum possible length for the fourth codeword?","[""$1$."", ""$2$."", ""$3$."", ""$4$.""]",A
+137,Let P be the statement ∀x(x>-3 -> x>3). Determine for which domain P evaluates to true:,"[""-3<x<3"", ""x>-3"", ""x>3"", ""None of the other options""]",C
+138,Let P be the statement ∀x(x>-3 -> x>3). Determine for which domain P evaluates to true:,"[""-3<x<3"", ""x>-3"", ""x>3"", ""None of the other options""]",C
+139,"Suppose we have the following function \(f: [0, 2] 	o [-\pi, \pi] \). \[f(x) = egin{cases}     x^2 &	ext{ for } 0\leq x < 1\     2-(x-2)^2 &	ext{ for } 1 \leq x \leq 2 \end{cases} \]","[""\\(f\\) is not injective and not surjective."", ""\\(f\\) is injective but not surjective."", ""\\(f\\) is surjective but not injective."", ""\\(f\\) is bijective.""]",B
+140,"If A is an uncountable set and B is an uncountable set, A − B cannot be :","[""countably infinite"", ""uncountable"", ""the null set"", ""none of the other options""]",D
+141,"If A is an uncountable set and B is an uncountable set, A − B cannot be :","[""countably infinite"", ""uncountable"", ""the null set"", ""none of the other options""]",D
+142,"You need to quickly find if a person's name is in a list: that contains both integers and strings such as:  list := [""Adam Smith"", ""Kurt Gödel"", 499, 999.95, ""Bertrand Arthur William Russell"", 19.99, ...]   What strategy can you use?","[""Insertion sort the list, then use binary search."", ""Bubble sort the list, then use binary search."", ""Use binary search."", ""Use linear search.""]",D
+143,What is the value of \(f(4)\) where \(f\) is defined as \(f(0) = f(1) = 1\) and \(f(n) = 2f(n - 1) + 3f(n - 2)\) for integers \(n \geq 2\)?,"[""41"", ""45"", ""39"", ""43""]",A
+144,"Which of the following are true regarding the lengths of integers in some base \(b\) (i.e., the number of digits base \(b\)) in different bases, given \(N = (FFFF)_{16}\)?","[""\\((N)_2\\) is of length 16"", ""\\((N)_{10}\\) is of length 40"", ""\\((N)_4\\) is of length 12"", ""\\((N)_4\\) is of length 4""]",A
+145,"Which of the following are true regarding the lengths of integers in some base \(b\) (i.e., the number of digits base \(b\)) in different bases, given \(N = (FFFF)_{16}\)? Question Options: 1. \((N)_2\) is of length 16 2. \((N)_{10}\) is of length 40 3. \((N)_4\) is of length 12 4. \((N)_4\) is of length 4","[""\\((N)_2\\) is of length 16"", ""\\((N)_{10}\\) is of length 40"", ""\\((N)_4\\) is of length 12"", ""\\((N)_4\\) is of length 4""]",A
+146,"In a lottery, a bucket of 10 numbered red balls and a bucket of 5 numbered green balls are used. Three red balls and two green balls are drawn (without replacement). What is the probability to win the lottery? (The order in which balls are drawn does not matter).","[""$$\frac{1}{14400}$$"", ""$$\frac{1}{7200}$$"", ""$$\frac{1}{1200}$$"", ""$$\frac{1}{1900}$$""]",C