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Judy has agreed to teach a ceramics class at a community art center if the enrol

ID: 3404931 • Letter: J

Question

Judy has agreed to teach a ceramics class at a community art center if the enrollment is at least 14 students, but not more than 35 students. If the enrollment is 14, she will charge every student a price of $90. Otherwise, for each student in excess of 14, she will lower the price of every student $3. So, for example, if she gets 2 extra students, then the price for every student will drop $6. Let x be the number of students enrolled in the class. Find a function p(x) that expressed the price that each student pays as a function of the number of students in the class. Find a function R(x) that expresses the revenue that Judy will receive as a function of the number of students in the class. What enrollment maximizes the revenue? How much will each student pay? How much revenue will Judy make?

Explanation / Answer

a)

Since the number of students must be atleast 14 and not more than 35

Let the number of students

P(x) = 90$, if x = 14

P(x) = 90 -3(x-14), 14 <= x <= 35

(x-14) represents the number of students more than 14, since Judy is dropping rate by $3 per student, hence we need to multiply it with -3

P(x) = 90 - 3x + 42

P(x) = 132 - 3x

b)

R(x) = Number of students * P(x)

=> x * (132 - 3x)

=> 132x - 3x^2

c)

Differentiatiing the function R(x) wrt x we get

R'(x) = 132 - 6x

Equating the derivative to zero, we get

132 = 6x

x = 22

Hence enrollment of 22 students maximizes the revenue

Each student will pay

P(22) = 132 - 3(22) = 132 - 66 = 66$

Revenue Judy will make

=> x * P(x)

=> 22 * 66

=> 1452$