Question

One cellular phone carrier charges $26.50 a month and $0.25 a minute for local calls. Another carrier charges $14.50 a month and $0.25 a minute for local calls. For how many minutes is the cost of the plans the same?

Answer 1

The cost of plans is same for 120 minutes.

Explanation:

Given:

One cellular phone charge = $26.50 a month and $0.15 per minute.

Another cellular charges = $14.50 a month and $0.25 per minute.

Let the number of minutes at which both plans are same be =
`x` minutes

For
`x` minutes the plan charges are as following:

1)
`$(26.50 + 0.15x)`

2)
`$(14.50 + 0.25x)`

So, we equate the above expressions as the plans are same.

`26.50 + 0.15x=14.50 + 0.25x`

Multiplying both sides by 100.

`100*(26.50 + 0.15x)=(14.50 + 0.25x)* 100`

`2650 + 15x=1450 + 25x`

Subtracting both sides by 1450.

`2650 + 15x-1450=1450 + 25x-1450`

`1200 + 15x=25x`

Subtracting both sides by
`15x`

`1200 + 15x-15x=25x-15x`

`1200=10x`

Dividing both sides by 10.

`(1200)/(10)=(10x)/(10)`

`120=x`

∴
`x=120\ minutes`

The cost of plans is same for 120 minutes.