can u plz help me with a pre-calc problem?

Question

a manager estimates that if the company charges p dollars for their new product, where 0

Answer 1

r(p) = 2000p - 10p^2

To determine the max/min values, you take the derivative, which yields:
2000 - 10 * (2p) = 0

to solve for "p":
2000 = 20p

p = 100