JAMB Economics 2011 Paper

Concept:Price elasticity of supply measures how much quantity supplied changes when the price changes.Explanation:From the table, initial price is $\mathrm{N}1$ and initial quantity supplied is $60$ units.New price is $\mathrm{N}2$ and new quantity supplied is $120$ units.Change in quantity supplied: $120 - 60 = 60$ units.Percentage change in quantity supplied: $\frac{60}{60} \times 100 = 100\%$.Change in price: $2 - 1 = 1$.Percentage change in price: $\frac{1}{1} \times 100 = 100\%$.Price elasticity of supply: $\frac{100\%}{100\%} = 1$.This means supply is unitary elastic.Answer:$1$ (Option C).