A merchant buys 30 kg of rice at Tk. 40/kg, and another 20 kg of rice at Tk. 30/kg. He mixes them and sells half of the mixture at Tk. 36/kg. At what price should he sell the remaining mixture to get an overall profit of 30%?

Question: A merchant buys 30 kg of rice at Tk. 40/kg, and another 20 kg of rice at Tk. 30/kg. He mixes them and sells half of the mixture at Tk. 36/kg. At what price should he sell the remaining mixture to get an overall profit of 30%?

Solution:
Total cost for the entire quantity of rice = (30 × 40) + (20 × 30) = 1200 + 600 = 1800
If his profit is 30%, then the sales realization = (130/100) × 1800 = 2340.
Total rice = 30 + 20 = 50 kg
He sells 25 kg at Tk. 36/kg = 900.

Therefore to make the said amount of profit, he should sell the remaining 25 kg of rice at 2340 - 900 = 1440