a bookseller sells his books at a 25 % markup in price . if he sells a book for $ 12.5 , how much did he pay for it ?
"let the cost price of book = x selling price of book = 12.5 $ markup % = 25 ( 125 / 100 ) x = 12.5 = > x = 10 answer e"
subtract(12.5, multiply(divide(25, const_100), 12.5))