One cell phone plan charges $35.99 per month, including 400 minutes of out-of-network calls each month. Each additional minute outside the network costs $0.25. Another plan charges $59.99 per month, including 1000 minutes of out-of-network calls per month. This plan charges $0.40 for each additional minute out of the network. Find the number of total minutes outside the network a customer must use for the plans to cost the same in a month.
A) 1840
B) 1400
C) 1000
D) 400
E) none of these

Question

Quizplus · Accepted Answer

The plans cost the same when the total cost of out-of-network minutes is the same. For the first plan, the total cost is $35.99 + $0.25(x - 400), where x is the number of total minutes outside the network. For the second plan, the total cost is $59.99 + $0.40(x - 1000). Setting these two expressions equal and solving for x gives x = 1840.

One Cell Phone Plan Charges $35