If (1/2)^25 (1/81)^k = 1/18^25, then k =
Options
A) 8	B) 12.5	C) 16	D) 24	E) 36

Rationale: "i ' m going to focus on denominator only . . ( 2 ^ 25 ) . ( ( 3 ^ 4 ) ^ k = 18 ^ 25 ( 2 ^ 25 ) . ( ( 3 ^ 4 k ) = ( 2 . 3 ^ 2 ) ^ 25 ( 2 ^ 25 ) . ( ( 3 ^ 4 k ) = ( 2 ^ 25 ) . ( 3 ^ 2 ) ^ 25 hence 4 k = 50 k = 12,5 answer b i hope it ' s quite clear"
Answer: B