A trader mixes 10 kg of rice at Rs. 20 per kg with 20 kg of rice of other variety at Rs.40 per kg and sells the mixture at Rs. 40 per kg. His profit percent is:
Choose one:
A) No profit, no loss  B) 5%  C) 8%  D) 20%  E) None of these
C.P. of 30 kg rice = Rs. (10 x 20 + 20 x 40) = Rs. 200 + 800 = Rs. 1000.   S.P. of 30 kg rice = Rs.30x 40 = Rs. 1200   Gain =200/1000x100% =20%.   Answer: Option 20%
<result>D</result>
A trader mixes 10 kg of rice at Rs. 20 per kg with 20 kg of rice of other variety at Rs.40 per kg and sells the mixture at Rs. 40 per kg. His profit percent is: