Question

Kala purchased a prepaid phone card for $15. Long distance calls cost $12 a minute using this card. Kala Use her card only once to make a long distance call. If the remaining credit on her card is $10.68, How many minutes did her call last?

Answer 1

Kala call lasted for 0.36 minutes

Solution:

Given that Kala purchased a prepaid phone card for $15

Long distance calls cost $12 a minute using this card.

If the remaining credit on her card is $10.68

To find: Number of minutes her call lasted

Let "x" be the number of minutes her call lasted

Cost of 1 minute = $ 12

Total balance = $15

Remaining balance = $ 10.68

So we can frame a equation as:

Total balance = Remaining balance + Cost of 1 minute x number of minutes her call lasted

`15 = 10.68 + 12 * x\\\\15 - 10.68 = 12x\\\\4.32 = 12x\\\\x = 0.36`

So her call lasted for 0.36 minutes