Rate of rice of quantity 280 kg = Rs. 15.60/kg Rate of rice of quantity 120 kg = Rs. 14.40/kg He want to earn a profit of Rs. 10.45/kg Rate of Mix to sell to get profit of 10.45 = 280 x 15 . 60 + 120 x 14 . 40 280 + 120 + 10 . 45 4368 + 1728 400 + 10 . 45 = > 15 . 24 + 10 . 45 = 25 . 69