how many posotive integer divide 2^7 x 3^8 such that they are not prime or 1,
thanks for any help
You got it!
How many positive integer divide such that they are not prime or 1?
There are 8 choices for the 2's: .
There are 9 choices for the 3's: .
Hence, there are: . choices for numbers of the form
But this includes: .
. . The rest are all composite.
Therefore, the answer is: .