Skip to main content
OlympiadHQ

Browse · harp

Print

imc

counting and probability intermediate

Problem

Three distinct integers are selected at random between and , inclusive. Which of the following is a correct statement about the probability that the product of the three integers is odd?
(A)
(B)
(C)
(D)
Solution
For the product to be odd, all three factors have to be odd. The probability of this is . , but and are slightly less than . Thus, the whole product is slightly less than , so .
Final answer
A