37 . if the cost price of 15 tables be equal to the selling price of 20 tables , the loss per cent is ?
let c . p . of each table = re . 1 c . p . of 20 tables = rs . 20 s . p . of 20 table = c . p . of 15 tables = rs . 15 loss = ( 5 / 20 ) x 100 % = 25 % answer : c
multiply(divide(subtract(20, 15), 20), const_100)