Question

A phone company offers two monthly charge plans. In plan a there is no monthly fee, but the customer pays 8 cents per minute of use. In Plan B the customer pays a monthly fee of $2.40 and then an additional 7 cents per minute of use. For what amount of monthly phone use will plan a cost more than plan b? Use m for the number of minutes of phone use in a month and solve your inequality for

Answer 1

`m>2.40`

Explanation:

Let m denotes the number of minutes of phone use in a month.

In plan a there is no monthly fee, but the customer pays 8 cents per minute of use.

Total cost of plan a =
`8m`

In Plan B the customer pays a monthly fee of $2.40 and then an additional 7 cents per minute of use.

Total cost of plan b =
`2.40+7m`

To find amount of monthly phone use for which plan a cost more than plan b, solve the inequality
`8m>2.40+7m`.

`8m>2.40+7m\\8m-7m>2.40\\m>2.40`