Jimmy is comparing two different cell phone companies: MyTalk and BMobile. Both company's monthly costs are shown.
Which company has a lower monthly cost? Which company had the lowest total cost after four months?

both answers are BMobile

MyTalk has a lower monthly cost. Based on the graph it seems to be about $25 a month.

MyTalk has a lower cost after 4 months. If you look at the graph, 4 months costs $130 whereas BMobile costs $170 after 4 months.