boy sells a book for rs . 720 he gets a loss of 10 % , to gain 10 % , what should be the sp ?
"cost price = 720 / 90 x 100 = 800 to gain 10 % = 800 x 10 / 100 = 80 sp = cp + gain = 800 + 80 = 880 answer : b"
add(divide(720, subtract(const_1, divide(10, const_100))), multiply(divide(720, subtract(const_1, divide(10, const_100))), divide(10, const_100)))