For each of the following cases, calculate the point price elasticity of demand

For each of the following cases, calculate the point price elasticity of demand, and state whetherdemand is elastic, inelastic, or unit elastic. The demand curve is given by
QD = 5,000 - 50PX

a. The price of the product is $50.
b. The price of the product is $75.
c. The price of the product is $25