I got the strategy to answer market sizing questions like "How many petrol stations are there in city xx"?". You take assumptions like the population, number of cars, number of cars a petrol station can serve, etc. But what about questions like "How many elephants are there in the world?" Despite saying "There are elephants in Africa, Asia and in Zoos", I would not know how to continue.
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Sometimes you have to make obvious assumptions or at least start with those.
You also always have to consider that for questions like this, a correct answer isn't the (mail) goal, but rather how you approach it. You can have different ways of answering a question that the interviewers will appreciate the same.
For instance, the elephant question was answered here (https://www.preplounge.com/en/consulting-forum/case-how-many-elephants-are-there-1056 ) and they made different assumptions
