A shop owner professes to sell his articles at certain cost price but he uses false weights with which he cheats by 15% while buying and by 20% while selling. What is his percentage profit?	Choose the correct choice from the following answers
A) 10.22 % B) 20.22 % C) 21.22 % D) 43.75 % E) ca n ' t be calculated

Rationale: "the owner buys 100 kg but actually gets 115 kg ; the owner sells 100 kg but actually gives 80 kg ; profit : ( 115 - 80 ) / 80 * 100 = ~ 43.75 % answer : d ."
Answer: D