Looks like one way to solve it with one specific idea of segmenting the population in the stadium. Important for you to force yourself to think about other possible segmentations (e.g. first a layer of country A and country B participants perhaps with different preferences for beer). The approach is the important part, not really the precise numbers.
Also important, whatever number you get, please sense-check it. Make sure to just be able to tell the interviewer why your number could too high or too low. This can be done by stress-testing your numerous assumptions or by quickly testing an entire different approach (in this case you used a bottom-up population-based approach, however there are always supply-based (top-down) approaches too, such as estimating how many beer stations there are in the stadium). You could for example try to calculate how much money now is made with your beer or what volume we are talking about in terms of barrels or truck loads. If youre numbers reveal you earn a high double-digit MILLION USD in beer revenues for a regular game, i.e. XX USD per visitor, you know you are likely too high for instance).
Most important - as any case interview, market estimations require you to have a DISCUSSION with the interviewer (on your approach, variables / assumptions, your math, your result, and the sense-check, potential next steps to improve the quality of the result). Do not just pick one approach and engange in a 20 minute monologue.
Looks like one way to solve it with one specific idea of segmenting the population in the stadium. Important for you to force yourself to think about other possible segmentations (e.g. first a layer of country A and country B participants perhaps with different preferences for beer). The approach is the important part, not really the precise numbers.
Also important, whatever number you get, please sense-check it. Make sure to just be able to tell the interviewer why your number could too high or too low. This can be done by stress-testing your numerous assumptions or by quickly testing an entire different approach (in this case you used a bottom-up population-based approach, however there are always supply-based (top-down) approaches too, such as estimating how many beer stations there are in the stadium). You could for example try to calculate how much money now is made with your beer or what volume we are talking about in terms of barrels or truck loads. If youre numbers reveal you earn a high double-digit MILLION USD in beer revenues for a regular game, i.e. XX USD per visitor, you know you are likely too high for instance).
Most important - as any case interview, market estimations require you to have a DISCUSSION with the interviewer (on your approach, variables / assumptions, your math, your result, and the sense-check, potential next steps to improve the quality of the result). Do not just pick one approach and engange in a 20 minute monologue.