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 $10.4g$, what is the weight of zinc?

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

Answer 1

Answer: (D)

. $\left(6.5g\right)$

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 $10.4g$.

$\Rightarrow 8x=10.4g$
$\Rightarrow x=\frac{10.4}{8}$
$\therefore x=1.3$
So, the weight of zinc alloy is $5x=5\times 1.3=6.5g$
Therefore, the weight of zinc is $6.5g$.