The variables represent positive integers, neither of which are divisible by 10 yet the product of is 100000. Find the sum of .
Source: mathcontest.olemiss.edu 1/12/2009
This problem is similar to the problem titled “Product of X and Y” dated 12/1/2008.
Since we want not divisible by 10, we should keep the 2’s and the 5’s separate when we form the two factors of 100000. Thus,
The sum .