The theory of the firm under perfect competition — Economics STD 12 Humanities & Commerce — Question

$\text{e}_\text{s}=\frac{\text{Percentage change in quantity supplied of a commodity}}{\text{Percentage change in its price}}$

$=\frac{\Delta\frac{\text{q}}{\text{q}}\times100}{\Delta\frac{\text{p}}{\text{p}}\times100}=\frac{\Delta\text{q}_\text{s}}{\Delta\text{p}}.\frac{\text{p}}{\text{q}_\text{s}}$

$\text{e}_\text{s}=\frac{\Delta\text{q}_\text{s}}{\Delta\text{p}}.\frac{\text{p}}{\text{q}}$

Example:

$\text{e}_\text{s}=\frac{\Delta\text{q}_\text{s}}{\Delta\text{p}}\times\frac{\text{p}}{\text{q}_\text{s}}=\frac{100}{10}\times \frac{10}{100}=1$