Question

For his long distance phone service, Ravi pays a $2 monthly fee plus 12¢ per minute. Last month, Ravi's long distance bill was $12.68. For how many minutes was Ravi billed?

Answer 1

`89\ \text{minutes}`

Explanation:

Let the number of minutes Ravi spoke for be
`x`

The fixed monthly fee is $2

Per minute Ravi is charged 12¢ = $0.12

The charge in a month will be

`y=2+0.12x`

In one month Ravi was billed $12.68. So
`y=12.68`

`12.68=2+0.12x\\\Rightarrow x=(12.68-2)/(0.12)\\\Rightarrow x=89\ \text{minutes}`

So, Ravi spoke for
`89\ \text{minutes}` that month.