The average weight of A, B and C is 45 kg. If the average weight of A and B be 40 kg and that of B and C be 43 kg, then the weight of B is___________? September 23, 2025 by Admin A. 17 kg B. 20 kg C. 26 kg D. 31 kg ✅ The correct answer is option D. 31 kg.