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?

Respuesta :

Answer:

$20

Step-by-step 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