Intermediate Microeconomics and Its Application 12th Edition by Walter Nicholson,Christopher Snyder

Exercise 20

Suppose that the market demand curve for pasta is a straight line of the form Q = 300 ? 50P where Q is the quantity of pasta bought in thousands of boxes per week and P is the price per box (in dollars).
a. At what price does the demand for pasta go to 0? Develop a numerical example to show that the demand for pasta is elastic at this point.
b. How much pasta is demanded at a price of $0? Develop a numerical example to show that demand is inelastic at this point.
c. How much pasta is demanded at a price of $3? Develop a numerical example that suggests that total spending on pasta is as large as possible at this price.