WAEC Agriculture 2018 Paper

Concept:Price elasticity of demand measures how much the quantity demanded responds to a change in price.Explanation:Original price is $P_0 = 12$ N and original quantity demanded is $Q_0 = 200$ kg.New price is $P_1 = 8$ N and new quantity demanded is $Q_1 = 240$ kg.Change in quantity is $\Delta Q = Q_1 - Q_0 = 240 - 200 = 40$ kg.Change in price is $\Delta P = P_1 - P_0 = 8 - 12 = -4$ N.Elasticity is calculated as the percentage change in quantity divided by the percentage change in price.So, elasticity $= \frac{\Delta Q / Q_0}{\Delta P / P_0} = \frac{40/200}{-4/12}$.This equals $\frac{0.2}{-0.333}$ which gives $-0.6$.Economists usually ignore the negative sign, so the elasticity is $0.6$.Answer:D. $0.6$