Question

A's income is '$20\%$' less than that of B, By what percent is B's income more than A's?

Answer 1

$\Rightarrow$It is given that A's income is '$20\%$' less than that of B, which means that A's income is '$80\%$' of B's income.

Let the income of B be '$\mathrm{x}$'.

$\therefore$ Income of A $=80\%$ of B's income

$=\frac{80\mathrm{x}}{100}=0.80\mathrm{x}$

$\Rightarrow$Percentage by which B's income is more than A$=\frac{\mathrm{Income}\mathrm{of}\mathrm{B}-\mathrm{Income}\mathrm{of}\mathrm{A}}{\mathrm{Income}\mathrm{of}\mathrm{A}}\times 100$

$$\begin{gathered} =\frac{\mathrm{x}-0.80\mathrm{x}}{0.80\mathrm{x}}\times 100 \\ =\frac{0.20\mathrm{x}}{0.80\mathrm{x}}\times 100 \\ =25\% \end{gathered}$$
Therefore, B’s income is '$25\%$' more than A's income.