IIMAthematical Interview!
The afternoon of March 9, 2024 is something I am going to remember and cherish for a long time to come. Walking around in a suit around the ultra-luxurious and expensive halls of Taj Bengal, Kolkata, final-year me felt so out of place as I waited for my turn to arrive. Its aftermath was also less than pleasant — I felt I had bombed my best shot at converting the best business school of India. Mom soothed me, Dad told me it had gone “solidly” — I wanted to believe them so badly.
Spoiler alert — it all worked out in the end. Lesson learnt: never trust your perceptions of a situation too absolutely.
A bit about my profile:
Class X (ICSE): 99% (All India Rank 3, West Bengal topper)
Class XII (ISC): 98.5% (Top 1% of my board)
Grad (Electrical Engineering at IIT Kharagpur): 86.6%
CAT percentile: 99.98
Analytical Writing Test:
Duration: 20 minutes
Word limit: 250–300
Topic: Assumptions of a man who claims Patanjali has done no harm by selling products which are supposed to cure blood pressure, diabetes etc because they are to be paired with lifestyle changes. Evidence in favour of and against the same.
Personal Interview:
Panelists (P1, P2): 2 (both male, middle-aged). M is me.
Duration: 30 minutes
Transcript:
P1 — So, long wait? Last candidate in the panel. Does it bother you?
M — No, sir, it’s fine
P1 — Where are you from?
M — Kolkata
P1 — Where in Kolkata?
M — Sir originally in […], now in […], near ISI
P1 — So why didn’t you study at ISI? It’s walking distance from your home
M — Sir I did not want to do my undergrad in maths. Besides, IIT was a childhood dream
P2 — So you don’t like maths?
M — I don’t mind it in moderation, but an undergrad in maths would be too heavy for me
P1 — But ISI has a lot of other things apart from math. It has stats, computer science, it’s very good in quantitative economics, you know
M — Oh. Okay sir
P2 — Also, IIT cannot be a childhood dream. What is good at IIT?
M — Sir the academics, personal development, skill-building opportunities like student clubs, alumni network and the all-round learning that happens there is very good
P1 — So why not do an MTech and a PhD from there, if you like it so much?
M — Sir, I am more inclined to do an MBA now
P1 — So, IIT education was the dream, not becoming an electrical engineer
M — Yes, sir
P2 — So now you would say IIM Ahmedabad is the dream. You have shifting dreams and aspirations
M — Yes, sir, that is right
P1 — What do you want to do at IIMA? Where do you see yourself in 5 years?
M — SIr, I have developed an interest in entrepreneurship, and I hope to take it further, by working at a startup or opening one myself. I have taken courses on entrepreneurship and communication in my final year. I have also participated in a B-plan competition where we had to design a business around sustainable fashion, and I liked the process. So I feel entrepreneurship is the way forward for me
P2 — But IIMA is not the best school for this purpose. There is […] school in the US for entrepreneurship. It is even better than Harvard and Chicago. You should go there
M — Sir, I want to stay in India. Also, getting foreign education is very expensive, so that is also an issue
P1 — IIMA is also very expensive. It’s not cheap!
M — Sir I have spoken to my seniors, and they also said that it’s expensive, so…
P2 — Also you can get scholarships. Many faculty at IIMA have gotten their degrees using scholarships. That is why the US is preferred over Europe for education
M — Oh. Okay sir
P1 — Tell me two qualities you have learned from your mother
M — (answered. He seemed satisfied)
P1 — Did you have any maths courses in your degree?
M — Yes, sir, I had one on probability
P1 — What all was there in the syllabus?
M — (told)
P1 — Okay, so you know what a probability density function is, right?
M — Yes, sir
P1 — Can a pdf have a value greater than 1? Draw it
M — Yes, sir (drew and explained)
P1 — Can a probability mass function have a value greater than 1?
M — No sir, because it consists of the probabilities of discrete events, probability of a discrete event cannot be more than 1
P1 — Okay. What distribution will have a mean always greater than its variance?
M — (drew and showed. He seemed satisfied)
P2 — Do you know what a binomial distribution is?
M — Sir I know the expression for its pmf. (wrote it)
P2 — What is its mean?
M — (thought for a while) Sorry sir, I cannot recall right now
P2 — We have interviewed 40 people today — 25 men and 15 women. What is the probability of selection of 5 women and 7 men? The probability of selection of any person is p = 0.1
M — (solved correctly, but with extra cancelling out 0.1s and 0.9s)
P2 — Is there redundant information?
M — Yes, sir, the value of p is redundant
P2 — Why is it the case?
M — Because it is equal for all people. Had it been different for men and women, it would not have been redundant
P2 — (indicating the expression for the final answer) What distribution is this?
M — I don’t know, sir. It may be Bernoulli distribution
P2 — No. What is the Bernoulli distribution?
M — (wrote down pmf, showed him and explained with coin, head-tail example)
P2 — So will it be right to say that the Bernoulli is an extension of the Binomial?
M — Actually, sir, it is the other way round
P2 — Okay. Differentiate e^|x|
M — (solved and showed)
P2 — Draw the graph of the function, and superimpose the graph of its derivative on it
M — (drew and showed)
P2 — Does this make sense?
M — No… actually yes, it does. (he was trying to wrong-foot me. Explained how it was correct)
P2 — So a function can be continuous and have a discontinuous derivative. Give me a function with a discontinuity but a continuous derivative
M — (thought, wrote him a function and showed. He nodded, but I realised later I had made a mistake)
P2 — Can you write me a theorem about this observation, generalising it so that it is true for all functions?
M — (wrote something. He nodded)
P2 — Okay, I am done. (motioned to P1)
P1 — Do you play any sport?
M — Sir, I have joined the gym this semester
P1 — Gym is not really a sport, you know. You should play a sport. IITs have such good facilities
M — Yes sir, I should. I just don’t have any interest as such in sports
P1 — Do you follow any sport?
M — Yes, sir, I follow cricket.
P1 — Yes, England series is going on…Bazball and all. But my question will not be on Bazball. What is the Corridor of Uncertainty?
M — (explained)
P1 — Do you know about the Duckworth-Lewis method?
M — Sir I don’t know the calculation process, but it depends on the overs left, wickets remaining, and how well the opposition were off at that stage in the game
P1 — Yes. Both Duckworth and Lewis were statisticians, you know
M — Oh. I see
P1 — Do you read any newspapers?
M — Sir I read the editorial of The Hindu
P1 — What is the GDP of India in USD?
M — Sir, it is $3.18 trillion.
P1 — It is more than that, it has crossed $3.5 trillion.
M — Sir I checked Google two days ago, I found the data there.
P1 — Maybe Google has not updated the data yet. What’s the GDP of the USA?
M — Sir, it is around $25 trillion.
P1 — Do you know anything about India and Russia?
M — Sir, I cannot recall anything of significance that has happened in the recent past
P1 — Recent does not matter. Tell me anything
M — Sir, India buys arms and weapons from Russia. We also import oil from Russia, and some time back the payment was made in rupees, which was significant.
P1 — Okay. Do you have any questions for us?
M — Sir, may I know your names?
P2 — We cannot disclose that as it is against rules.
M — Okay sir. Thank you.
(I got the famous IIMA toffee. It was an Eclair :P)
A few tips:
Keep calm, be fast and keep communicating your thought process with the interviewers. Don’t let long or awkward silences creep into the conversation. You can usually tell whether your answer is right or wrong from the reaction of the interviewers. Tweak it accordingly. Never try to lie to them — they can see right through it and will absolutely tear you down if they notice you trying.
Your perception of how the interview is going is not necessarily what the interviewer thinks about it.
