Nellibell's Café bakes croissants that are sold to local restaurants and grocery stores in the Columbia, South Carolina area. When 600 croissants are baked, the average cost is $0.70. When 720 croissants are baked, the average cost is $0.65. What is the total cost when 670 croissants are baked?
A) $568.
B) $588.
C) $448.
D) $532.
E) $500.

Question

Quizplus · Accepted Answer

First, we need to use the information given to set up a system of equations. Let x be the fixed cost and y be the variable cost per croissant. Then we have:

600y + x = 420
720y + x = 468

Subtracting the first equation from the second, we get:

120y = 48
y = 0.4

Substituting y = 0.4 into the first equation, we get:

600(0.4) + x = 420
x = 180

So the cost equation for Nellibell's Café is:

C = 0.4Q + 180

where C is the total cost and Q is the number of croissants baked.

Plugging in Q = 670, we get:

C = 0.4(670) + 180
C = 448

Therefore, the total cost when 670 croissants are baked is $448, and the best choice is C.

Nellibell's Café Bakes Croissants That Are Sold to Local Restaurants