Let the price of B per kg ₹ x. Then, the price of A per kg = ₹ 3x 1 kg of C contains 2/7 kg of A and 5/7 kg of B Price of 1 kg of C = (2/7) × 3x + (5/7)x = (11 / 7)x By the given condition, 11x / 7 = 5.20 – 0.80 = ₹ 4.40 ⇒ x = 4.40 × (7/11) = ₹ 2.80 Hence the price of B per kg = ₹ 2.80.