Basic Rental is $50 a day plus$0.20 a mile. Roadrunner is $20 aday plus$0.50 a mile. To rent the same truck. How many miles must be drivenin a day. To make the rental coast for Basic rental a better deal than that for roadrunner

1. Calculate the total cost of driving each truck. Specify an unknown (X) for the number of miles to drive.

2. Set the cost of driving of the basic equal to the cost of driving the roadrunner.

3. Solve for X - the number of miles to drive.

BR = $50 a day plus $0.20 a mile.
RR = $20 aday plus $0.50 a mile.

The cross-over point per day is where the cost for either supplier is equal.
Call that daily milage x.
BR : 50 + 0,2x
RR : 20 + 0,5x
At cross-over point these costs are equal.
So 50 + 0,2x = 20 + 0,5x
It is now easy to calculate the value of x.

Note that there could be more to this, if this rental is related to use by a delivery service : there is an additional cost of diesel per mile and cost of labour per hour. Against that, there is an additional income (delivery charges).