Answer :

Given:

An alloy contains copper and zinc in a ratio of 3:7. The total mass of the alloy is 750g.

Required:

Find the mass of the metal in 750g of alloy.

Explanation:​

Let the mass of the metal is x gm.

The weight of copper = 3x

The weight of zinc= 7x

Total weight

[tex]\begin{gathered} 3x+7x=750 \\ 10x=750 \\ x=\frac{750}{10} \\ x=75\text{ gm} \end{gathered}[/tex]