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.