Answer:
a. 65 seats
b. $422.50
Step-by-step explanation:
We have the following two functions:
8 * x, {0 <= x <= 50}
x * (8 - 0.1 * (x - 50)), {x> 50}, solving we have:
-0.1 * x ^ 2 + 13 * x, {x> 50}
Now we derive both functions and we are left with:
8, {0 <= x <= 50}
-0.2 * x + 13 {x> 50}
we cannot equal to 0 the first function that is equal to 0, because it would be inconsistent, therefore we equal the second function to 0:
-0.2 * x + 13 = 0
0.2 * x = - 13
x = -13 / -0.2
x = 65
Now, test for increasing and decreasing on the intervals (0.65) and (65, infinity)
p '(60) = -0.2 * (60) + 13 = 1
since this value is positive the profit is increasing on (0.65)
p '(70) = -0.2 * (70) + 13 = -1
becuase this value is negative the profit is decreasing on (65, infinity)
Therefore 65 seats are needed to maximize profit
The maximum value would be:
P (65) = 0.1 * (65 ^ 2) + 13 * 65 = 422.5
That is, the maximum value is $ 422.50