If N = 2^0.15 and N^b = 64, b must equal  Choices: A) 3 / 80 B) 3 / 5 C) 40 D) 5 / 3 E) 80 / 3

Rationale: "15 / 100 = 3 / 20 n = 2 ^ 3 / 20 n ^ b = 2 ^ 6 ( 2 ^ 3 / 20 ) ^ b = 2 ^ 6 b = 40 answer : c"
Answer: C