Carcass wrote:
How many different positive integers are factors of 225 ?
(A) 4
(B) 6
(C) 7
(D) 9
(E) 11
-------ASIDE--------------
If N = (p^a)(q^b)(r^c)..., where p, q, r,...(etc.) are prime numbers, then the total number of positive divisors of N is equal to (a+1)(b+1)(c+1)...Example: 14000 = (2^
4)(5^
3)(7^
1)
So, the number of positive divisors of 14000 = (
4+1)(
3+1)(
1+1) = (5)(4)(2) = 40
-------------------------
225= (3^
2)(5^
2)
So, the number of positive divisors of 225 = (
2+1)(
2+1) = (3)(3) = 9
Answer: D