Question

The ratio of weights of zinc and copper in an alloy is 5:8. If the weight of copper in a sample of this alloy is 12 g, what is the weight of zinc?

• A. 6.5 g
• B. 6 g
• C. 7 g
• D. 7.5 g

Answer 1

The correct option is D

7.5 g

Given : Ratio of weights of zinc and copper = 5 : 8

Let the weights be 5x and 8x.

Now, its given that the weight of copper in a sample of this alloy is 12 g.

$\Rightarrow$ 8x = 12 g
$\Rightarrow$ x = $\frac{12}{8}$
$\Rightarrow$ x = 1.5
$\Rightarrow$ 5x = 5 $\times$ 1.5 = 7.5 g
$\therefore$ The weight of zinc is 7.5 g.