15) If goods A and B are perfect substitutes, then the marginal rate of substitution of
good A for good B is constant.
a.True
b.False
16) Roger owns a small health store that sells vitamins in a perfectly competitive
market. If vitamins sell for $12 per bottle and the average total cost per bottle is $11.50
at the profit-maximizing output level, then in the long run
a.more firms will enter the market.
b.some firms will exit from the market.
c.the equilibrium price per bottle will rise
d.average total costs will rise.
17) When supply and demand both increase, equilibrium
a.price will increase.
b.price will decrease.
c.quantity may increase, decrease, or remain unchanged.
d.price may increase, decrease, or remain unchanged.