Two types of wheat, A and B, are priced at Rs. 9 per kg and Rs. 15 per kg respectively. They are combined in a ratio of 3:7. If 5 kg of this blend is sold at a 25% gain, what is the profit earned?

Explanation

Assume the quantities of wheat A and B mixed are 3x kg and 7x kg respectively. The cost for 3x kg of A is Rs. 9 × 3x = Rs. 27x. The cost for 7x kg of B is Rs. 15 × 7x = Rs. 105x. Therefore, the total cost for 10x kg of the mixture is Rs. 27x + Rs. 105x = Rs. 132x. The cost of 5 kg of the mixture is (132x / 10x) × 5 = Rs. 66. Selling this 5 kg at a 25% profit yields a profit of 25% of Rs. 66, which equals Rs. 16.50.