Question

An alloy contains only Zinc and Copper and they are in the ratio of 7:9.

If the weight of the alloy is 8 kg, then find the weight of Copper in the alloy

Answer 1

Given, the ratio of Zinc and Copper in alloy = 7:9 and weight of alloy = 8 kg
Let the weight of Zinc and Copper in alloy be 7x and 9x respectively, where x is multiple of weight.
Then, total weight = 7x + 9x = 16x
$\therefore 16x=8kg\Rightarrow x=\frac{1}{2}kg$
$\therefore$ Weight of copper = $9x$ = $9\times \frac{1}{2}=4\frac{1}{2}kg$
Hence, the weight of copper is $4\frac{1}{2}kg$.