The highest-income fifth of the U.S. population earns more than 50 percent of all income

Last year, Joan bought 50 pounds of hamburger when her household income was $40,000. This year, her household income was only $30,000 and Joan bought 60 pounds of hamburger

Holding everything else constant, Joan's income elasticity of demand for hamburger is A) negative, so Joan considers hamburger to be an inferior good. B) negative, so Joan considers hamburger to be a normal good. C) positive, so Joan considers hamburger to be an inferior good. D) positive, so Joan considers hamburger to be a normal good and a necessity.

We can find the market demand for pears by:

a. adding up all the prices people are willing to pay for pears. b. multiplying the number of people times the price of pears. c. adding up the number of pears that producers are willing to sell. d. multiplying the number of pears by the price of pears. e. adding up all the individual demand curves for pears.