Primo car rental agency charges 30 dollars per day plus 0.25 dollars per mile. Ultimo car rental agency charges 20 dollars per day plus 0.80 dollars per mile. Find the daily mileage for which the Ultimo charge is three times the Primo charge.
Let m be the number of miles driven.
Primo: 30 + 0.25m
Ultimo: 20 + 0.8m
The Ultimo charge is three times the Primo charge:
20 + 0.8m = 3(30 + 0.25m)
20 + 0.8m = 90 + 0.75m
0.05m = 70
m = 1400 miles