The following function gives the total cost of a water bill dependent on the amount of time (t) in hours that the water runs.

Question

C(t) = 4(0.21)^t

A. What does C(t) represent in the context of this problem?

B. What does t = 5 represent in the context of this problem?

C. What does C(5) mean in the context of this problem?

D. Does finding C(-2) make sense in the context of this problem?

Answer 1

A. C(t) represents the total cost of the water bill in dollars.

B. t = 5 represents the amount of time in hours that the water runs.

C. C(5) means finding the total cost of the water bill after the water has been running for 5 hours.

D. Finding C(-2) does not make sense in the context of this problem because time cannot be negative for the water to be running.