Lemon Motors has been selling an average of 60 new cars per month at $800 over the factory price. They are considering an increase in this markup. A marketing survey indicates that for every $20 increase, they will sell one less car each month. What should their new markup be to maximize income?
I know I have to complete the square to find the maximum, but I just can't think of an equation to describe the situation.
got it thanks! can you check out my 2 other questions?