Calculate the price elasticity of demand using both point and arc elasticity formulas for the given points A (P=60, Q=20) and B (P=15, Q=40).

Here are the solutions to the questions:

Question One A: Price Elasticity of Demand

The formula for point elasticity of demand is $E_p = \frac{\Delta Q}{\Delta P} \times \frac{P}{Q}$.
The formula for arc elasticity of demand is $E_p = \frac{Q_2 - Q_1}{P_2 - P_1} \times \frac{P_1 + P_2}{Q_1 + Q_2}$.

Given points:
Point A: $P_A = 60$, $Q_A = 20$
Point B: $P_B = 15$, $Q_B = 40