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September 2025 term · Machine Learning Foundations · BSCS2004

Machine Learning Foundations End Term: 21 December 2025 (September 2025 term)

The IIT Madras BS Machine Learning Foundations (MLF) End Term paper sat on 21 Dec 2025, in the September 2025 term: 38 questions for 86 marks in 180 minutes. Every question is below with its answer. Take it as a timed mock test to be marked, or read it through first.

Questions
38
Marks
86
Duration
180 min
MCQ
15
MSQ
4
Written
19

Updated

Official paper: Machine Learning Foundations 18 Dec 25 · No negative marking.

Question 1

+3 marksOne correct option

Consider the function defined as . For what values of is convex

  1. A

    —

  2. B

    —

  3. C
    Figure from the original question paper
  4. D
    Figure from the original question paper
Show answer

Correct answer

  • A

    —

Question 2

+4 marksOne correct option

A real estate company wants to create a model to predict house prices based on the size of the house. They collect data from three recent sales. There are two features: size (hundreds of sq ft) and number of bedrooms. The data-matrix and the price vector (in hundreds of thousands of rupees) are:

The objective is to find the weight vector that minimizes the sum of squared errors given by the loss function:

If is the value that minimizes , then which of the following is ?

A real estate company wants to create a model to predict house prices based on the size of the house. They collect data
A real estate company wants to create a model to predict house prices based on the size of the house. They collect data
  1. A
    Figure from the original question paper
  2. B
    Figure from the original question paper
  3. C
    Figure from the original question paper
  4. D
    Figure from the original question paper
Show answer

Correct answer

  • A
    Figure from the original question paper

Question 3

+3 marksOne or more correct options

Consider

Which of the following is/are true

Consider

Select all that apply.

  1. A

    is Hermitian.

  2. B

    is unitary.

  3. C

    is positive semi-definite.

  4. D

    is positive definite.

  5. E

    is invertible.

Show answer

Correct answers

  • A

    is Hermitian.

  • C

    is positive semi-definite.

Question 4

+3 marksOne correct option

Let . Find the directional derivative of at the point in the direction of unit vector along .

  1. A
    Figure from the original question paper
  2. B
    Figure from the original question paper
  3. C
    Figure from the original question paper
  4. D
    Figure from the original question paper
Show answer

Correct answer

  • A
    Figure from the original question paper

Question 5

+3 marksWritten answer

An ML team wants to predict whether an email is spam or not by using some classification models. Therefore, the team defines three binary features where, = Presence of suspicious keywords (1 = present, 0 = absent)• = Whether the sender is unknown (1 = unknown, 0 = known)• = Whether the email contains a link (1 = yes, 0 = no)• The team collects the following dataset from previously classified emails:

The model makes a prediction using the rule : and

Compute the average loss on this dataset. Enter your answer correct to one decimal place.

An ML team wants to predict whether an email is spam  or not  by using some classification models. Therefore, the team d
An ML team wants to predict whether an email is spam  or not  by using some classification models. Therefore, the team d
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A written answer, not marked automatically.

Question 6

+1 markOne correct option

Consider the convex hull of the set of points . Which of the following points belongs to the convex hull?

  1. A

    —

  2. B

    —

  3. C

    —

  4. D

    —

Show answer

Correct answer

  • A

    —

Question 7

+3 marksWritten answer

Let be a continuous random variable with the probability density function:

What is the value of

Let  be a continuous random variable with the probability density function:
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Question 8

+3 marksOne or more correct options

If is a square invertible matrix, which of the following is/are true?

Select all that apply.

  1. A

    The row space of is equal to its column space.

  2. B

    The nullspace of is equal to its left nullspace.

  3. C

    The left nullspace of is equal to its row space.

  4. D

    The nullspace of is equal to its row space.

Show answer

Correct answers

  • A

    The row space of is equal to its column space.

  • B

    The nullspace of is equal to its left nullspace.

Question 9

+3 marksWritten answer

is a matrix whose eigenvalues are . Consider the set as defined below:

Find .

is a  matrix whose eigenvalues are  . Consider the set  as defined below:
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Question 10

+3 marksWritten answer

An analyst monitors the number of defective items produced daily. Let denote number of defective items produced in a day. Using Markov's inequality, the analyst finds an upper bound of on the probability that at least items are defective. Calculate the mean of .

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Question 11

+3 marksWritten answer

Using the method of Lagrange multipliers, find a point on the circle centered at with radius that is closest to the point . If this distance is , enter as your answer. Your answer should be an integer.

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Question 12

+3 marksWritten answer

Consider two datasets in , and , each having three points as shown below. The figure is drawn to scale. PCA is run on both these datasets separately.

and are the covariance matrices of the two datasets respectively. If is the eigenvector corresponding to the largest eigenvalue of and is the eigenvector corresponding to the smallest eigenvalue of , find the absolute value of . Both eigenvectors have unit norm. Your answer should be an integer.

Consider two datasets in  ,  and  , each having three points as shown below. The figure is drawn to scale. PCA is run on
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Question 13

+3 marksOne correct option

A cafe records the time (in minutes) a customer waits for a freshly made sandwich. The waiting time follows an exponential distribution with mean 5 minutes. Based on the above data, answer the given subquestions.

Find the waiting time such that 95% of customers are served within minutes.

  1. A
    Figure from the original question paper
  2. B

    —

  3. C
    Figure from the original question paper
  4. D

    —

Show answer

Correct answer

  • B

    —

Question 14

+3 marksWritten answer

The time (in minutes) a bank employee spends assisting a customer follows an exponential distribution with parameter . The time spent (in minutes) from a random sample of 5 customers are as follows: Find the maximum likelihood estimate of for the given sample. Enter the answer correct to two decimal places.

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A written answer, not marked automatically.

Question 15

+2 marksOne correct option

A cafe records the time (in minutes) a customer waits for a freshly made sandwich. The waiting time follows an exponential distribution with mean 5 minutes. Based on the above data, answer the given subquestions.

What is the probability that a randomly chosen customer waits between and minutes

  1. A

    —

  2. B

    —

  3. C

    —

  4. D

    —

Show answer

Correct answer

  • D

    —

Question 16

+4 marksWritten answer

Anil throws a dart onto a circular board. Let a random variable denote the distance from the center to the point where the dart hits the board. Suppose the PDF of is

Calculate the value of

. Enter the answer correct to two decimal places.

Anil throws a dart onto a circular board. Let a random variable  denote the distance from the center to the point where
Anil throws a dart onto a circular board. Let a random variable  denote the distance from the center to the point where
Show answer

A written answer, not marked automatically.

Question 17

+2 marksWritten answer

A cafe records the time (in minutes) a customer waits for a freshly made sandwich. The waiting time follows an exponential distribution with mean 5 minutes. Based on the above data, answer the given subquestions.

Using Chebyshev's inequality, find an upper bound for , where represents the mean of the random variable . Enter your answer correct to two decimal places.

Show answer

A written answer, not marked automatically.

Question 18

+3 marksWritten answer

Using the method of Lagrange multipliers, find a point on the circle centered at with radius that is closest to the point . If this distance is , enter as your answer. Your answer should be an integer.

Show answer

A written answer, not marked automatically.

Question 19

+2 marksOne or more correct options

Consider the following constrained optimization problem:

Answer the sub-questions assuming that we take a very small step in the direction of interest.

Consider the following constrained optimization problem:

At the point which of the following is/are descent directions for the objective function

Select all that apply.

  1. A

    —

  2. B

    —

  3. C

    —

  4. D

    —

Show answer

Correct answers

  • A

    —

  • C

    —

Question 20

+3 marksWritten answer

Consider the following constrained optimization problem:

If

corresponds to the global minimum, find

. Enter your answer correct to one decimal place.

Consider the following constrained optimization problem:
Consider the following constrained optimization problem:
Consider the following constrained optimization problem:
Show answer

A written answer, not marked automatically.

Question 21

+2 marksOne or more correct options

Consider the following constrained optimization problem:

Answer the sub-questions assuming that we take a very small step in the direction of interest.

Consider the following constrained optimization problem:

At the point which of the following is/are feasible directions

Select all that apply.

  1. A

    —

  2. B

    —

  3. C

    —

  4. D

    —

Show answer

Correct answers

  • A

    —

  • C

    —

Question 22

+1 markOne correct option

If and , where

Based on the above data, answer the given subquestions.

If  and  , where

What is the distribution of

  1. A

    Normal

  2. B

    Normal

  3. C

    Normal

  4. D

    Normal

Show answer

Correct answer

  • C

    Normal

Question 23

+1 markOne correct option

Consider the following constrained optimization problem:

Answer the sub-questions assuming that we take a very small step in the direction of interest.

Consider the following constrained optimization problem:

Is a potential candidate at which the problem could have a local minimum

  1. A

    Yes

  2. B

    No

Show answer

Correct answer

  • B

    No

Question 24

+2 marksOne correct option

If and , where

Based on the above data, answer the given subquestions.

If  and  , where

What is the distribution of

  1. A

    Normal

  2. B

    Normal

  3. C

    Normal

  4. D

    Insufficient information.

Show answer

Correct answer

  • C

    Normal

Question 25

+1 markOne correct option

If and , where

Based on the above data, answer the given subquestions.

If  and  , where

What is the distribution of

  1. A

    Normal

  2. B

    Normal

  3. C

    Normal

  4. D

    Normal

Show answer

Correct answer

  • B

    Normal

Question 26

+2 marksOne correct option

If and , where

Based on the above data, answer the given subquestions.

If  and  , where

Find the covariance matrix of .

  1. A
    Figure from the original question paper
  2. B
    Figure from the original question paper
  3. C
    Figure from the original question paper
  4. D
    Figure from the original question paper
Show answer

Correct answer

  • B
    Figure from the original question paper

Question 27

+2 marksOne correct option

If and , where

Based on the above data, answer the given subquestions.

If  and  , where

What is the distribution of

  1. A

    Normal

  2. B

    Normal

  3. C

    Normal

  4. D

    Insufficient information.

Show answer

Correct answer

  • A

    Normal

Question 28

+2 marksOne correct option

A company aims to minimize its production cost, represented by the following quadratic function: The company applies the gradient descent algorithm to minimize this function, starting with an initial guess of and using a step size (learning rate) of

, where Based on the above data, answer the given subquestions.

A company aims to minimize its production cost, represented by the following quadratic function:  The company applies th

Find the updated point after the first iteration of the gradient descent algorithm.

  1. A

    —

  2. B

    —

  3. C

    —

  4. D

    —

Show answer

Correct answer

  • B

    —

Question 29

+2 marksOne correct option

If and , where

Based on the above data, answer the given subquestions.

If  and  , where

Find the covariance matrix of .

  1. A
    Figure from the original question paper
  2. B
    Figure from the original question paper
  3. C
    Figure from the original question paper
  4. D
    Figure from the original question paper
Show answer

Correct answer

  • A
    Figure from the original question paper

Question 30

+3 marksWritten answer

A company aims to minimize its production cost, represented by the following quadratic function: The company applies the gradient descent algorithm to minimize this function, starting with an initial guess of and using a step size (learning rate) of

, where Based on the above data, answer the given subquestions.

A company aims to minimize its production cost, represented by the following quadratic function:  The company applies th

Compute the value of after the second iteration, i.e., .

Show answer

A written answer, not marked automatically.

Question 31

+2 marksOne correct option

A company aims to minimize its production cost, represented by the following quadratic function: The company applies the gradient descent algorithm to minimize this function, starting with an initial guess of and using a step size (learning rate) of

, where Based on the above data, answer the given subquestions.

A company aims to minimize its production cost, represented by the following quadratic function:  The company applies th

Find the updated point after the first iteration of the gradient descent algorithm.

  1. A

    —

  2. B

    —

  3. C

    —

  4. D

    —

Show answer

Correct answer

  • B

    —

Question 32

+3 marksWritten answer

A company aims to minimize its production cost, represented by the following quadratic function: The company applies the gradient descent algorithm to minimize this function, starting with an initial guess of and using a step size (learning rate) of

, where Based on the above data, answer the given subquestions.

A company aims to minimize its production cost, represented by the following quadratic function:  The company applies th

Compute the value of after the second iteration, i.e., .

Show answer

A written answer, not marked automatically.

Question 33

+1 markWritten answer

A cafe records the time (in minutes) a customer waits for a freshly made sandwich. The waiting time follows an exponential distribution with mean 5 minutes. Based on the above data, answer the given subquestions.

Show answer

A written answer, not marked automatically.

Question 34

+1 markWritten answer

Consider the following constrained optimization problem:

Answer the sub-questions assuming that we take a very small step in the direction of interest.

Consider the following constrained optimization problem:
Show answer

A written answer, not marked automatically.

Question 35

+1 markWritten answer

If and , where

Based on the above data, answer the given subquestions.

If  and  , where
Show answer

A written answer, not marked automatically.

Question 36

+1 markWritten answer

A company aims to minimize its production cost, represented by the following quadratic function: The company applies the gradient descent algorithm to minimize this function, starting with an initial guess of and using a step size (learning rate) of

, where Based on the above data, answer the given subquestions.

A company aims to minimize its production cost, represented by the following quadratic function:  The company applies th
Show answer

A written answer, not marked automatically.

Question 37

+1 markWritten answer

If and , where

Based on the above data, answer the given subquestions.

If  and  , where
Show answer

A written answer, not marked automatically.

Question 38

+1 markWritten answer

A company aims to minimize its production cost, represented by the following quadratic function: The company applies the gradient descent algorithm to minimize this function, starting with an initial guess of and using a step size (learning rate) of

, where Based on the above data, answer the given subquestions.

A company aims to minimize its production cost, represented by the following quadratic function:  The company applies th
Show answer

A written answer, not marked automatically.