Customers of a phone company can choose between two service plans for long distance calls. The first plan has a

Question

$14 monthly fee and charges an additional
$0.20 for each minute of calls. The second plan has an $18 monthly fee and charges an additional $0.15 for each minute of calls. For how many minutes of calls will the costs of the two plans be equal?

Answer 1

let m be the number of minutes

cost1 = .20m + 14
cost2 = .15m + 18

When is .20m + 14 = .15m + 18 ?

.05m = 4
m = 4/.05 = 80

Answer 2

250