a person buys an article at $ 1200 . at what price should he sell the article so as to make a profit of 40 % ?
c 1680 cost price = $ 1200 profit = 40 % of 1200 = $ 480 selling price = cost price + profit = 1200 + 480 = 1680
add(1200, multiply(1200, divide(40, const_100)))