Question

An alloy of copper and zinc contains $$45\%$$ copper and the rest zinc. Find the weight of zinc in $$20$$ kg of the alloy.

Answer 1

Total weight of the alloy $$= 20$$ kg

Percentage of copper $$= 45\%$$

So, percentage of zinc $$= (100 – 45)\%$$

$$= 55\%$$

As total quantity is always $$100\%$$

Thus, weight of zinc $$= \dfrac{55}{100} \times 20 = \dfrac{110 }{ 10}$$

$$= 11\,kg$$

Therefore, the weight of zinc in the alloy is $$11\, kg$$