[denzil]

Unlike the car question, where you can assume the car is at home and so the most probable answer is to drive, with the machines it gets complicated. Since the question doesn't specify if each machine makes one part or if they depend on each other (which is pretty common for parts production). If they are in series and the time to first part is different than time to produce 5 parts, the answer for 100 machines would be the time to produce the first part. Where if each machine is independent and takes 5 minutes to produce single part, the time would be 5 minutes.

[Drupon]

You passed the intelligence check and failed the wisdom one.

The key technique in the mathematical method to answer the machine question is "theory of mind".

[krisoft]

Theory of mind won’t help you answering this question. It is obviously an underspecified question (at least in any contexts where you are not actively designing/thinking about some specific industrial process). As such theory of mind indicates that the person asking you is either not aware that they are asking an underspecified question, or are out to get you with a trick. In the first case it is better to ask clarifying question. In the second case your choosen answer depend on your temperament. You can play along with them, or answer an intentionally ridiculous answer, or just kick them in the shin to stop them messing with you.

There is nothing “mathematical” about any of this though.

[oytis]

It's not theory of mind, it's an understanding of how trick questions are structured and how to answer one. Pretty useless knowledge after high school - no wonder AI companies didn't bother training their models for that