Question

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

Answer 1

Step : Finding the weight of zinc in $20kg$ of the alloy

Given,
Total weight of the alloy $=20kg$.
Percentage of copper $=45\%$.
As total quantity is always $100\%$.
So, percentage of zinc in alloy $=(100-45)\%=55\%$.
$\therefore$ Weight of zinc $=55\%$ of $20Kg$.
$=\frac{55}{100}\times 20=\frac{110}{10}kg=11kg$

Hence, the weight of zinc in the alloy is $11kg$.