Answer all questions. Explain all steps. No assumptions.

4. (15 points) Madeleine's demand function for milk shakes is equal to q =10 p. a) (5 points) Derive the own-price elasticity of demand. b) (5 points) What is the own-price elasticity of demand when the price of a milk shake is $0? Is Madeleine's demand elastic or inelastic? Explain your answer. c) (5 points) What does the own-price elasticity of demand approach as the price of a milk shake approaches $10? Is Madeleine's demand elastic or inelastic? Explain your