Question

The ratio of zinc and copper in an alloy is 9:8. If the weight of copper, in the same alloy, is 120 kg, find the weight of zinc in the alloy.

Answer 1

If $x$ is the weight of zinc, then according to the problem
9 : 8 = $x$ : 120 ​

⇒ $\frac{9}{8}=\frac{x}{120}$

⇒ $8x=9\times 120$

⇒ $x=\frac{(9\times 120)}{8}=135kg$

​