a person buys an article at rs . 500 . at what price should he sell the article so as to make a profit of 40 % ?
"cost price = rs . 500 profit = 40 % of 500 = rs . 200 selling price = cost price + profit = 500 + 200 = 700 answer : a"
add(500, multiply(500, divide(40, const_100)))