During junior year in college my buddy and I had an interview at the same bank.
About halfway through the interview they asked, “How good are your math skills?”
I said, “They’re alright, but my qualitative skills are better.” (Truth be told, I knew my math skills were inferior to my peers’).
So they asked me one math question, “What’s the square root of one thousand?” I reasoned that it must be above 30 and below 40, closer to 30 (because 30 times 30 is 900, and 40 times 40 is 1600). They seemed satisfied with my answer and we moved on.
When I talked to my buddy after the interview he said they asked him the same question,“How good are your math skills?”
Except he answered, “They’re really good.” (He thought this was the right answer because it was an interview and he needed to be impressive.)
So they drilled him with math questions. He answered the first few right (I probably couldn’t have even gotten that many), but eventually he started getting them wrong and it broke his confidence for the rest of the interview.
Underpromise and overdeliver (especially with managers and investors). You don’t want to sell yourself too short, but just long enough to meet minimum expectations and then you can really make an impression when you exceed what was expected.