Question

A bookstore is deciding what price it should charge for a certain book. After research, the store finds that if the book's price is $p$ dollars (where $p \le 40$), then the number of books sold per month is $120-3p$. What price should the store charge to maximize its revenue?

Answer 1

$20

Explanation:

revenue would be price * quantity

p ( 120-3p)

-3p^2 + 120p = revenue max will occur at p = - b/2a = - 120/((2)(-3))

p max rev = 20