Question 100515
Denise has a fixed cost per month of $29.95. Subtract the fixed cost from her monthly bill of $99.95 to get a timed cost of $70.00.
At 10c per minute she has been charged for 7000/10 = 700 minutes of chargable time.
She does not get charged for the first 300 minutes so she has used her phone for 300 + 700 = 1000 minutes. (16 2/3 hours)