If ratio between the change in price & change in quantity demanded is 0.25. The consumer demands 100 units at an initial price of Rs 10 per unit. Calculate the price elasticity of demand.

(-) 0.025 (-) 0.040 (-) 0.40 (-) 0.25

(-) 0.40

$PED = \frac{ΔQ}{ΔP}×\frac{P}{Q}$ Given $\frac{ΔP}{ΔQ}=0.25$ $∴\frac{ΔQ}{ΔP}=4$ $∴PED=4×\frac{10}{100}=0.4$