A piece of alloy weighs 8 kg. It contains tin and copper and their weights are in the ratio of 3 ∶ 1. If the amount of tin is reduced by half, what is the new weight of the piece?
1). 7 kg
2). 6 kg
3). 5 kg
4). 4 kg
Let the weight of tin and copper be 3x kg and 1x kg respectively.
3x + 1x = 8
⇒ x = 2
∴ Weight of tin = 6 kg and weight of copper = 2 kg
New quantity of tin = 3 kg
∴ New weight of the piece = 3 kg + 2 kg = 5 kg