Find the odds against correctly guessing the answer to a multiple choice question with 6 possible answers.

Answer 1

with 5 wrong answers = 5/6

Answer 2

With odds against, the chances of the event not occurring go in the numerator, and the chances of it happening are in the denominator. So (5/6)/(1/6), and when you divide the fractions and simplify you get 5/1 or 5:1.