A shop owner professes to sell his articles at certain cost price but he uses false weights with which he cheats by 12% while buying and by 20% while selling. What is his percentage profit?	Choose the correct answer.
A) 10.22%  B) 20.22%  C) 21.22%  D) 40%  E) Can't be calculated
The owner buys 100 kg but actually gets 112kg;   The owner sells 100 kg but actually gives 80kg;   Profit:   (112-80)/80*100= 
<gadget id="calculator">  (112-80)/80*100</gadget>
<output>40</output>
~40%   Answer: 40%.
<result>D</result>
A shop owner professes to sell his articles at certain cost price but he uses false weights with which he cheats by 12% while buying and by 20% while selling. What is his percentage profit?