Problem:
How many ordered pairs of positive integers  satisfy the equation 
Answer Choices:
A. 
B. 
C. 
D. 
E. 
Solution:
Multiplying the given equation by gives . The divisors of are , and . Each of these divisors can be paired with a divisor to make a product of . Hence there are ordered pairs .
The problems on this page are the property of the MAA's American Mathematics Competitions