I have no idea where to start!

*A quick quiz consists of 3 multiple choice problems, each of which has 4 answers, only one of which is correct. If you make random guesses on all 3 problems,

(a) What is the probability that all 3 of your answers are incorrect?

(b) What is the probability that all 3 of your answers are correct?

2 answers

a) The prob that a guess is wrong is 3/4

so the prob that none are correct, that is, all 3 are wrong is (3/4)(3/4)(3/4) = 27/64.

b) then the prob that all 3 are guessed correctly is (1/4)(1/4)(1/4) = 1/64
Okay great thank you so much that makes much more sense!