Do you give people the formula and just have them implement it? That seems just like a weird test to see if you have the stdlib of your language memorized or no

Do you give people the formula and just have them implement it? That seems just like a weird test to see if you have the stdlib of your language memorized or not. And if you don't give them the formula it seems like you're just testing their memory of 8th grade [pre?] algebra. Regardless that sounds like a question I would probably get right (maybe not to your bar though) and then remove myself from consideration based on inane interviewing. The best interview loop I was ever on was for my current job. 45-ish minutes in coderpad with a staff engineer going over actual data and writing a few actually-used methods doing specific things. A 90-ish minute system design session with a few senior SREs designing a feature that already existed but had a lot of interesting edge cases. And a 60 minute behavioral interview with a couple managers. On the longer side but all on different days and all using real-world things from that job. Google whatever you want to google. Ask whatever questions you want to ask. Nothing remotely approaching a quiz, gotcha questions, inane trivia or unrelated math.