Question

A multiple choice test consists of six questions, each of which has four choices. Each question has exactly one correct answer.

William guesses randomly at each answer. What is the probability that he gets four or fewer questions correct?

Answer 1

To get 4 or fewer correct, at least 2 answers have to be wrong. And the probability of that is:
3/4 x 3/4=9/16
1-9/16=probability that 4 or fewer are correct=7/16 ☺☺☺☺