The C.P of 15 books is equal to the S.P of 20 books. Find his gain% or loss%? Select:  A) 25 % loss  B) 16 2 / 8 % loss  C) 16 3 / 3 % loss  D) 36 2 / 3 % loss  E) 56 2 / 3 % loss

Rationale: "15 cp = 20 sp 20 - - - 5 cp loss 100 - - - ? = > 25 % loss answer : a"
Answer: A