Given, The weights of 3 boxes are 4, 5 & 11 kilograms Calculation: Possible combinations of the weight - All 3 boxes = 4 + 5 + 11 = 20 kg 2 boxes (4 kg, 11 kg) = 4 + 11 = 15 kg 2 boxes (5 kg, 11 kg) = 5 + 11 = 16 kg ∴ Any combination of the boxes cannot make weight 17 kg.