Supply and demand curves are in Figure $6.37 .$ A price of
$\$ 40$ is artificially imposed.
(a) At the 840 price, estimate the consumer surplus, the producer surplus, and the total gains from trade.
(b) Compare your answers in this problem to your answers in Problem $10 .$ Discuss the effect of price controls on the consumer surplus, producer surplus, and gains from trade in this case.