TestMagic Forums - View Single Post - Help me understand this one, please from Powerprep

tomintampa · 2009 July 1st, 04:27 PM

1) How many positive integers can be expressed as a product of two or more of the prime numbers 5, 7, 11, and 13 if no one product is to include the same prime factor more than once?

A) eight B) nine C) ten D) eleven E) twelve

Answer is D

I have seen the mechanics on solving it but im not sure WHY, can someone help? Thank you.

2009 July 1st, 04:27 PM	#1 (permalink)
tomintampa Within my grasp! Join Date: Aug 2006 Posts: 139	Help me understand this one, please from Powerprep 1) How many positive integers can be expressed as a product of two or more of the prime numbers 5, 7, 11, and 13 if no one product is to include the same prime factor more than once? A) eight B) nine C) ten D) eleven E) twelve Answer is D I have seen the mechanics on solving it but im not sure WHY, can someone help? Thank you.