Carcass wrote:
How many different positive integers are factors of 441 ?
A. 4
B. 6
C. 7
D. 9
E. 11
----ASIDE---------------------
If the
prime factorization of N = (p^
a)(q^
b)(r^
c) . . . (where p, q, r, etc are different prime numbers), then N has a total of (
a+1)(
b+1)(
c+1)(etc) positive divisors.
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
-----ONTO THE QUESTION!!----------------------------
441 = (3)(3)(7)(7) = (3^
2)(7^
2)
So, the number of positive divisors of 441 = (
2+1)(
2+1)
= (3)(3)
= 9
Answer: D
Cheers,
Brent