For all real numbers v, an operation is defined by the equation v* = v - v/3. If (v*)* = 20, then v= Choose the most appropriate option
A) 36	B) 39	C) 42	D) 45	E) 48

Rationale: "( v * ) * = ( v - v / 3 ) - ( v - v / 3 ) / 3 20 = 2 v / 3 - 2 v / 9 = 4 v / 9 v = 45 the answer is d ."
Answer: D