# IIT Gandhinagar MTech(Regular) Interview Experience 2021

Firstly, there was an online written test on 11th May 2021. The test was in 2 parts.

**Part 1 :**

In the 1st part, there were 30 MCQ questions each with 1 mark and a penalty of -1 for each incorrect answer.

The MCQs were mostly GATE level.

The majority of topics covered were

- DSA
- Discrete Maths
- Probability.
- A few questions were from CO, OS, CN, and TOC (1-2 questions each).

**Part 2 : **(Not used for evaluation and shortlisting, only for interview purposes)

Three subjective questions were there:

- Let us assume you are the head of Google and decide to build the next version of Google Meet. What features will you use/improve? How can you leverage skills from 3-4 CS subjects to improve the product?
- There are 100 rooms in a hotel. The hotel manager is lazy. When a customer requests a room, the manager picks a room from 1 to 100 uniformly at random without even bothering to check whether it is already occupied. If the room is already occupied, the customer is asked to leave the hotel. Otherwise, they can check-in. Suppose 100 customers try to check in, one by one, to the hotel. Show that the expected number of occupants is at least 50.
- The IPL season is on, but with the COVID situation, you prefer not to go inside the crowded stadiums. The field where the match is played is surrounded by a wall height K. Outside, there are N boxes (numbered 1 through N). For each valid i, the i-th box has a height H[i]. You want to take some boxes and stack them on top of each other to build two towers. The height of each tower is the sum of the heights of all the boxes that form it. Of course, no box can be in both towers. The height of each tower should be at least K. so that you can watch the match from the top of these towers (you want to build two towers for backup, just so you can switch if you are bored, or use the other one if the first collapses). What is the smallest number of boxes required to build two towers such that each of them has a height of at least K? Or is it impossible altogether? Describe an algorithm to solve this problem: argue the correctness and the running time of your approach.

**I was shortlisted for the interviews. My slot was on 14th May 2021, at 10:30 am.**

There were 3-panel members. But only two of them asked questions. I will address them as I1 and I2. So the interview went like this –

**I1:** Please give a brief introduction about yourself.**Me:** I gave a short 1-minute introduction about my college, my homeplace, and my interests in computer science subjects.\**I1:** About which subjects you want us to ask questions?**Me:** Linear Algebra, Probability, Data Structures.**I2:** Ok Subham, let’s start with the basics. What are eigenvalues and eigenvectors?**Me:** I explained with geometric intuition.**I2:** Ok. Suppose you are given a diagonal matrix, what can you tell about the eigenvalues?**Me:** The diagonal elements are the eigenvalues of the matrix.**I2:** Can you prove that?**Me:** I give an intuitive proof using the concept that the determinant of the matrix = product of eigenvalues.**I2:** Ok. Now, let’s move to probability. What are disjoint events?**Me:** Explained that if A ∩ B = 0, then the events are disjoint.**I2:** Let’s suppose you are given a probability of two events, A and B. P(A) = 0.9 and P(B) = 0.9. Can you say that these events are disjoint events?**Me: **I** **couldn’t answer that question. (This was the easiest question of the whole interview ) Due to panic, I couldn’t answer.**I2:** Ok. Let’s now move back to Linear Algebra. Suppose you are given 3 vectors of 2 dimensions. Is it possible that they are linearly independent?**Me:** I explained with the rank concept.**I2:** Referring to I1, would you like to ask any questions?**I1:** Ya sure. So Subham, given a binary tree, how can you find the height of the tree?**Me: **I explained the recursive approach.**I1:** What is the time complexity?**Me:** I answered that in both the worst case and best case, it will be O(n).**I1:** OK, we are done. You can leave the meeting.**Me:** Thank you, sir.

They asked subjective test questions from some students. But they didn’t ask me.

Waiting for results….

**Tips for future aspirants:**

- Don’t panic, they will give you enough time to think, just think freely.
- Be sure you are good with each and every aspect of the subjects you are mentioning.
- For written tests, keep in touch and keep revising your GATE subjects after the GATE exam also.
- BEST OF LUCK…