Sourav purchased 30 kg rice at the rate of Rs. 10 per kg. and 35 kg. at the rate of Rs. 11 per kg. He mixed the two.At what price per kg. (in Rs.) should he sell the mixture to make a 30% profit in the transaction?

First calculate total cost: (30 kg × Rs. 10/kg) + (35 kg × Rs. 11/kg) = Rs. 300 + Rs. 385 = Rs. 685. Total weight = 30 + 35 = 65 kg. Cost price per kg = Rs. 685/65 = Rs. 10.54. For 30% profit, selling price = 10.54 × 1.30 ≈ Rs. 13.7 per kg. Option A (12.5) would give less than 20% profit, while B (13) gives about 23% profit.