The dollar price for a barrel of oil sold at a certain oil refinery tends to follow the demand equation below, where x is the number of barrels of oil on hand (in millions). ​
(Each question is individual. NOT MULTIPLE CHOICE.)
a) How much should be charged for a barrel of oil if there are 9 million barrels on ​ hand?
​b) What quantity x will maximize​ revenue? ​
c) What price should be charged in order to maximize​ revenue?

p = - 1/10 x + 74