1.3 Test Algebra

Question

Sergio's internet provider charges its customers $15 per month plus 4¢ per minute of on-line usage. Sergio received a bill from the provider covering a  period and was charged a total of $101.00. How many minutes did he spend on-line during that period? (Round to the nearest whole minute, if necessary.)

Answer 1

15 + .04m = 101/5 = 20.2 dollars per month

.04m = 20.2-15 = 5.2

m = 5.2/.04 = 52/.4 =520/4 = 130 minutes per month

5m = 650 minutes over the 5 month period. but likely mistake in method

or

5(15) + .04m = 110

.04m = 110 - 75 = 35

m = 35/.04 = 875 minutes

one of the two. go with 875