McKinsey & Company Junior Associate Interview Questions and Answers for Freshers

Round: Case Study Interview
Experience: Partner had been told to test me on case. During Q&A, I asked him about how Mckinsey treats innovation (since I come from an R&D background). He found the Q different. Was able to engage with him on that and had a healthy chat. My second Q completely resonated with him. I asked him how Mckinsey treated candidates with above avg exp. To that he talked about his own story (had joined consulting after 10 yrs industry exp.) and how it just changes the ramp rate. This question set up a good rapport between us and I could sense some good vibes at the end.

Recommended Approach
I took my time to come up with a structure. Start with population of city, segment it into 2 parts working professionals and non-working people (housewives, students,etc) I suggested I would estimate the # of people in each segment and then estimate the total # of rides they would take and based on the average time taken for an auto ride, I will find the total # of autos in the city. Sameer was OK with this plan. I started with Mumbai and said Sion and ahead autos were not allowed. So I suggested we should use only 50% of the population (around 7.5 million) to estimate # of autos. He was pleased that I used some practical knowledge also. From there on it was relatively straightforward. One place I made an assumption that 15% of working professional would use an auto. He wanted to know how I made this assumption. I realised that was a mistake on my part to make such an assumption. I then split the working professional segment to different income classes and then put a % for each to figure out how many from each sub-segment would take an auto.

The final # for working prof segment came around 50000 autos (assuming around 30min for a one-way ride, and on average 50% of autos have a single passenger and 50% have 2 passengers). He told me to double it to include the other segment. He asked whether this 100K was a reasonable estimate and what single question I would ask to see if this was reasonable. I was suggesting Qs which would not directly answer and more elaborate. Finally I suggested we could look at # of taxis in the city to get a comparable. He wanted one more question. At this point I was drained out. He helped me arrived at the question. (look at another city with comparable population) In retrospect these look trivial but I was unable to think so simple.
Tips: DONTs: Do not make assumption without any reasoning behind it. Don't think complicated. Keep your though process simple. Most of the times the interviewer is asking for fundamental stuff, nothing complicated

DOs: Lay out the structure especially in guestimate with as much detailed layering as possible before you crunch the #s. The interviewer will tell you how much detail he wants you to focus on. Engage the interviewer in the discussion as at every point he might give you some data to simplify your calculations.

Skills:
College Name: Indian School Of Business (ISB)