Answer:
1 hour
Explanation:
The trip is 225 km long, and your speed is 90 km/h. The time it takes to complete the trip without stopping is:
t = (225 km) / (90 km/h)
t = 2.5 hours
t = 150 minutes
You must complete the trip is 210 minutes, so you can afford to stop for 60 minutes, or 1 hour.
