How many of the positive divisors of 720 are also multiples of 4 not including 720? Answers:
A) 11 B) 12 C) 17 D) 18 E) 24
720 = 2^6 * 3 * 5 = (4) * 2^2 * 3^2 * 5   Besides (4), the exponents of 2, 3, and 5 are 2, 2, and 1.   There are (2+1)(2+1)(1+1) = 18 ways to make multiples of 4.   We must subtract 1 because one of these multiples is 720.   The answer is 17.
<result>C</result>
How many of the positive divisors of 720 are also multiples of 4 not including 720?