Question

An alloy consists of 30% zinc, 45% nickel and the rest copper. Find the mass of copper in 400 g of alloy​

Answer 1

According to question,

Percentage of Zn = 30%

Percentage of Ni = 45%

So,

Percentage of Cu = 100 - (30 + 45)

= 100 - 75

= 25%

Now in 400g of the alloy

$mass \: of \: copper = 25\% \: of \: 400g \\ = \frac{25}{100} \times 400g \\ = 25 \times 4g \\ = 100g$

$\therefore \: the \: mass \: of \: copper \: in \: 400g \: \\ of \: the \: alloy \: is \: 100g$