Let us assume the number of hours after which the cost of Pam and Michelle will be same = x Now let us concentrate on the information's already given in the problem. Fixed charge taken by Pam = $125 Charge per hour taken by Pam = $15 Fixed charge taken by Michelle = $50 Charge per hour taken by Michelle = $20 Then 125 + 15x = 50 + 20x 20x - 15x = 125 - 50 5x = 75 x = 75/5 = 15 So after 15 hours the charge taken by Pam and Michelle will be the same. I hope the procedure for doing this type of problem is clear to you.
