In what ratio should Assam Tea costing Rs. 300 per kg be mixed with Darjeeling Tea costing Rs. 400 per kg, so that by selling the mixture at Rs. 408 per kg there is gain of 20%.

Given: Assam Tea costing Rs. 300 per kg be mixed with Darjeeling Tea costing Rs. 400 per kg. Selling the mixture at Rs. 408 per kg. There is gain of 20%. Concept used: Basic concept of ratio of distribution. Calculation : From the given data, Selling price of mixture is Rs. 408 per kg Profit% = (selling price/Cost price – 1) × 100 ⇒ 20 = {(408/Cost price) – 1} × 100 ⇒ 0.2 + 1 = 408/Cost price ⇒ Cost price of mixture = 408/1.2 = Rs.340 per kg ∴ Ratio of Assam Tea to the Darjeeling Tea = (400 - 340) : (340 - 300) = 60 : 40 = 3 : 2 ∴ The ratio should be 3 : 2. Earned 20% on Rs. 408 Cost price of sold team is, ⇒ 100/120 × 408 ⇒ Rs. 340 By allegation method, ⇒ 60 : 40 ⇒ 3 : 2 ∴ The ratio is 3 : 2.