The demand function for a certain kind of mattress is given by p = 600e^−0.04x

where p is the unit price in dollars and x (in units of a hundred) is the quantity

demanded each month.

(a) Find the number of mattresses demanded per month if the unit price is

set at $250 per mattress.

(b) Use the results of part (a) to find the consumers’ surplus if the selling

price is set at $250 per mattress.