How many different positive integers are factors of 256 ?	Choose the correct answer:
A) 4  B) 6  C) 8  D) 16  E) 18
16×16=4^2 × 4^2   So total factors = (3+1)(3+1) = 16   Answer: 16
<result>D</result>
How many different positive integers are factors of 256 ?