Seela bought 2 kg of White tea at Rs. 20 per kg and 4 kg of Assam tea at Rs. 40 per kg. What profit percentage did she get when she mixed both varieties of tea together and sold it at Rs. 40 per kg?

Given : Seela bought 2 kg of white tea at Rs. 20 per kg and 4 kg of Assam tea at Rs. 40 per kg. calculation : The total cost price of 2 kg white tea at Rs. 20 per kg = 2 × 20 = Rs. 40 The total cost price of 4 kg Assam tea at Rs. 40 per kg = 4 × 40 = Rs. 160 He mixed the two varieties together. Then total cost price of (2 + 4) = 6 kg tea mixture = 40 + 160 = Rs. 200 So, the cost price of the mixture per kg = 200/6 = Rs. 100/3 If he sold the mixture at Rs. 40 per kg, he got a profit of Rs. (40 – 100/3) = Rs. 20/3 per kg. ∴ The required profit percentage = (20/3)/(100/3) × 100 = 20%