A student gives swimming lessons at the local club. One summer the club charged $40 and enrolled 1,000 kids. The next summer the managers decided to raise the fee to $50, and only 400 swimmers enrolled. The managers of the club should have thought about the price elasticity of demand for lessons. If the managers had realized how high the elasticity of demand for their product is, they might have avoided a half-empty pool.

A. Calculate the price elasticity of demand.

B. It seems that elasticity of demand is very high. Give some reasons why it might have been this big.