Problem:
What is the probability that an integer in the set is divisible by and not divisible by
Answer Choices:
A.
B.
C.
D.
E.
Solution:
Of the integers that are divisible by , there are that are divisible by both and . So there are that are divisible by and not by , and .
Answer: .
The problems on this page are the property of the MAA's American Mathematics Competitions