The greatest common factor of two numbers is 5!. Which of the following can be the second number, if one of the numbers is 6!?
Pick.
A) 3(5!)  B) 5(5!)  C) 4(5!)  D) 6(5!)  E) 7(5!)
GCF is the product of common factors of the numbers involved.   GCF = 5!   a = 6! = 6*5!   b will certainly have 5! and cannot have any more common factors with a (as this will increase the GCF)   Looking at the answers only 5 (5!) and 6! will have GCF as 5!   Ans 5(5!)
<result>B</result>
The greatest common factor of two numbers is 5!. Which of the following can be the second number, if one of the numbers is 6!?