Question 453695
an art museum charges $10 for an adult admission.  The museum estimates they will lose 15 adult visitors per day for each one dollar increase in price.  If the museum averages 300 adult visitors a day, which is the most profitable adult admission price?

Let x = the admission price
Then the number of visitors will be 300 - 15(x-10) [300 for x=10, 285 for x=11, etc.]
The total revenue will be:
R = x(300 - 15(x-10))
R = 300x - 15x^2 + 150x
R = 450x - 15x^2
To maximize the profit, we set dR/dx = 0 and solve for x:
dR/dx = 0 = 450 - 30x
This gives x = 15
So the most profitable price is $15
The graph of the revenue function is below:
{{{graph(300,300,-20,20,-200,3600,450x-15x^2)}}}