Question

a quiz had 6 questions, each with 4 possible answers (only one of which is correct). If you answer them at random, find the probability that all are correct and at least one is wrong.

Answer 1

I assume you want two answers,since "all are correct and at least one is wrong" is impossible.

P(all correct) = 1/4^6
P(some wrong) = 1 - P(all correct)