• question_answer 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 10.4 g, what is the weight of zinc? A) 6.5g                      B) 6gC) 7g                        D) 7.5g

Ratio of weights of zinc and copper = 5 : 8 Let the weights be $5x$ and $8x$. Given $8x\text{ }=\text{ }10.4$ $\Rightarrow x=\frac{10.4}{8}=1.5$ $\therefore$Weight of zinc $=\text{ }5x\text{ }=\text{ }5\text{ }\times \text{ }1.5\text{ }=\text{ }7.5g$