I’ve found in interviews you can just declare your assumptions for the things you don’t know. Ultimately these sorts of job interview questions are designed to

I’ve found in interviews you can just declare your assumptions for the things you don’t know. Ultimately these sorts of job interview questions are designed to evoke a response that can let you demonstrate how you would go about solving/explaining the problem; actually solving it correctly is rarely required or expected. I’d just say having never seen a 747, for purposes of the calculation let’s assume they are 300m long with a 10m diameter etc etc and proceed to do a terrible job of calculating how many ping pong balls fit.