Question

Christine purchased a prepaid phone card for $30. Long distance calls cost 18 cents a minute using this card. Christine used her card only once to make a long distance call. If the remaining credit on her card is $27.84, how many minutes did her call last?

Answer 1

The answer is 12 minutes.

Explanation:

It is given that the cost of one minute is $0.18. Firstly, you have to substract the remaing credits from her original credits :

$30 - $27.84 = $2.16

We have found out that she uses $2.16 for her long distance call. Next, you have to divide 18 cents from the uses in order to find out how many minutes she use :

`1 \: min = 0.18dollar`

`x \: mins = 2.16dollars`

`x = 2.16 / 0.18`

`x = 12 \: mins`

Answer 2

The call lasted 12 minutes. 12x0.18=2.16. 30.00-2.16=$27.84