For his phone service, Deshaun pays a monthly fee of $17, and he pays an additional $0.04 per minute of use. The least he has been charged in a month is $67.44.

Not sure what you are looking for, but the difference between $67.44 & the monthly fee of $17 would be the cost of the charge of minutes he spent talking on the phone. 67.44 - 17.00 = $50.44

50.44/ .04 = 1,261 minutes he talked on the phone.