Compasslabs interview questions

had two people interview me first guy was relaxed, but asked technical advertising terms & formulas that I never properly learned (like difference between CPC and CTR). I definitely got destroyed on that part. the second guy came in and asked me typical corporation trick questions (i.e. if you have two sand hourglasses, one being 4 minutes, and the other being 7 minutes, how would you make exactly 9 minutes?) both were really friendly guys with extensive badass resume backgrounds though, I just didn't do my homework and prepared hard enough