On my phone screen a Google recruiter asked me "how much is 2^24", and I knew the answer by heart and answered immediately.
So he asked "how did you figure this out so fast?". I told him I didn't, I just remember all the "important" powers of 2. He said "well... that's not what I was looking for, I wanted you to calculate it, but... I guess a candidate who memorizes powers of 2 is a positive sign?". I passed.
haha, I got that question too, in stead I worked in MPLS for over 5 years, I know by heart that MPLS label has 20bits which translates to 1 million labels, times 2^4 that is 16 million. The recruiter asked me how I figured it out so fast, I explained to him, that recruiter had no idea of what I was talking about. I did not pass.
So he asked "how did you figure this out so fast?". I told him I didn't, I just remember all the "important" powers of 2. He said "well... that's not what I was looking for, I wanted you to calculate it, but... I guess a candidate who memorizes powers of 2 is a positive sign?". I passed.