Question

4.5g of an alloy of copper and zinc contains 3.5g of copper.what weight of copper will there be in 18.9g of alloy?

Answer 1

4.5 g of alloy contains 3.5 gm
so 1 gm of an alloy will contain 3.5/4.5 gm of copper=7/9 gm of copper
so 18.9 gm of alloy will contain (7/9)*18.9 gm of copper =14.7 gm of copper.

Answer 2

Answer:

14.7 g of copper will there be in 18.9 g of alloy.            

Step-by-step explanation:

Given : 4.5 g of an alloy of copper and zinc contains 3.5 g of copper.

To find : What weight of copper will there be in 18.9 g of alloy?

Solution :

According to question,

Applying Unitary method,

4.5 g of an alloy of copper and zinc contains 3.5 g of copper.

1 g of an alloy of copper and zinc contains $\frac{3.5}{4.5}$ g of copper.

18.9 g of an alloy of copper and zinc contains $\frac{3.5}{4.5}\times 18.9$ g of copper.

18.9 g of an alloy of copper and zinc contains 14.7 g of copper.

Therefore, 14.7 g of copper will there be in 18.9 g of alloy.