If the quantity demanded of sunglasses decreases by 2% when average incomes fall by 10%, then we know that sunglasses are a) an inferior good. b) a normal good. c) a Giffen good. d) perfectly elastic.

Which of the following best explains why the demand for housing is more flexible than the supply? a. new housing developments are being constructed all the time. b. low interest rates for mortgages make buying a home very affordable. c. the increasing population always drives demand upwards. d. people can move more easily than producers can build new homes.