For her phone service, Kala pays a monthly fee of $13 , and she pays an additional $0.05 per minute of use. The least she has been charged in a month is $63.15 . What are the possible numbers of minutes she has used her phone in a month? Use m for the number of minutes, and solve your inequality for m .
The inequality would be 0.05m + 13 >= 63.15. Solving: 0.05m >= 50.15 m >= 1003 minutes Therefore at least 1003 minutes were consumed to be billed $63.15 or more. Hope this helps.