Alloy X has copper and zinc in the ratio 3 : 1, and alloy Y in the ratio 1 : 1. They are melted together in the ratio 2 : 3 by weight. What is the ratio of copper to zinc in the new alloy?

Explanation

1. 01

   Take 2 kg of X and 3 kg of Y. Copper: $2 \times \frac{3}{4} + 3 \times \frac{1}{2} = 3$ kg; zinc: $2 \times \frac{1}{4} + 3 \times \frac{1}{2} = 2$ kg.

2. 02

   Copper : zinc $= 3 : 2$.