One phone plan charges a $20 monthly fee and $0.08 per minute on every phone call made. Another phone plan charges a $12 monthly fee and $0.12 per minute for each call. After how many minutes would the charge be the same for both plans?
A. 60 minutes B. 90 minutes C. 120 minutes D. 200 minutes
200 minutes-let m represent the minutes of the phone calls. the monthly charge for the first plan is 20 + 0.08m. the monthly charge for the second plan is 12 + 0.12m. when the monthly charges are the same, 20 + 0.08m = 12 + 0.12m. solve for m to find the number of minutes both plans have the same rate.10 + 0.08m - 0.08m = 12 + 0.12m - 0.08m 20 = 12 + 0.04m 20 - 12 = 12 + 0.04m - 12 8 = 0.04m so m = 8/0.04 = 800/4 = 200 minutes