Kala purchased a prepaid phone card for $30. Long distance calls cost 9 cents a minute using this card. Kala used her card only once to make a long distance call. If the remaining credit on her card is$28.83, how many minutes did her call last?

Answer: Her call lasted 13 minutes.

Step-by-step explanation: Kala purchased a prepaid card with $30 worth of talk time. For long distance calls, the card is charged (deduction) 9 cents per minute.

At the time Kala had only $28.83 left on her prepaid card, she had spent the following;

Call charge = 30.00 - 28.83

Call charge = 1.17

Since the calls are charged in cents, we shall convert the amount spent to the appropriate unit, which is cents.

Note that $1.17 equals 117 cents (1.17 x 100).

A minute's call would cost 9 cents, and this means a call that cost 117 cents can be calculated as follows;

Charge per min = Total charge/9

Charge per min = 117/9

Charge per min = 13

Therefore her call lasted for 13 minutes.

The call lasted 13 minutes

Step-by-step explanation:

In this question, we are told to find the number of minutes a call lasted.

The initial amount on the card is $30 and after making a phone call just once, the balance went down to $28.83

What was used would be 30 - 28.83 = $1.17 or simply 117 cents

Now these long calls come at a cost of 9 cents per minute and we have a total of 117 cents here; the number of minutes is thus 117/9 = 13

This means Kala spent 13 minutes on the call