Subject: mathqa
Question: a trader cheats both his supplier and customer by using faulty weights . when he buys from the supplier , he takes 30 % more than the indicated weight . when he sells to his customer , he gives the customer a weight such that 40 % of that is added to the weight , the weight claimed by the trader is obtained . if he charges the cost price of the weight that he claims , find his profit percentage .
Option: 
A: 24.33 %
B: 29.109 %
C: 82 %
D: 28 %
Answer: C