A bookseller sells his books at a 15% markup in price. If he sells a book for $23.00, how much did he pay for it?  Choose one:
A) $ 14.40
B) $ 14.00
C) $ 21.00
D) $ 19.60
E) $ 20.00

Rationale: "let the cost price of book = x selling price of book = 23 $ markup % = 15 ( 115 / 100 ) x = 23 = > x = 20 answer e"
Answer: E