Question

A car can be rented from agency A at $85 per day plus $0.10 a mile or from agency B at $40 a day plus $0.20 a mile. If the car is driven m miles, for what values of m does it cost less to rent from agency A?

Answer 1

eg 10 miles,
A: 85+0.1*10=86
B:40+0.2*10=42

eg 100 miles 
A: 85+0.1*100=95
B:40+0.2*100=60

eg 450 miles 
A: 85+0.1*450=130
B:40+0.2*450=130

so for it to cost less to rent from agency A, m has to be bigger than 450 miles