Problem: a shop owner professes to sell his articles at certain cost price but he uses false weights with which he cheats by 50 % while buying and by 10 % while selling . what is his percentage profit ?
Rationale: "the owner buys 100 kg but actually gets 150 kg ; the owner sells 100 kg but actually gives 90 kg ; profit : ( 150 - 90 ) / 90 * 100 = 50 % answer : d ."
annotated_formula: divide(multiply(subtract(add(const_100, 50), subtract(const_100, 10)), const_100), subtract(const_100, 10))