Question

In a certain city, the monthly cost of telephone service is given the function C = 0.10n + 18, where n is the number of calls, 10 cents is the cost per call, and $14 is a fixed charge. Find the cost of making 60 calls a month.

Answer 1

The cost of making 60 calls a month is $20.

Explanation:

There was a small typing mistake there. If the fixed charge is $14, the cost of n calls is given by the following equation:

`C(n) = 0.1n + 14`

Find the cost of making 60 calls a month.

This is C(60), that is, C when n = 60. So

`C(n) = 0.1n + 14`

`C(60) = 0.1*60 + 14 = 20`

The cost of making 60 calls a month is $20.