Tom drives a truck. His regular trip is a distance of 280 km. He drives at an average speed of 80 km/h. For safety reasons Tom’s boss puts a speed limiter on his truck. This reduces Tom’s average speed by 10 km/h. How much longer will it take Tom to drive his regular trip?
Distance = 280 km
Average speed = 10 km/h
Time = Distance / Speed
Time = 280 km / 80 km/h
= 3.5 hours.
If the driver's speed reduced by 10 km/h, speed = 80 - 10 = 70 km/h
Time = Distance / Speed
Time = 280 km / 70 km/h
= 4 hours.
The time would be longer by : 4 - 3.5 = 0.5 hours.
0.5 * 60 = 30 minutes.
It would be longer by 0.5 hours or 30 minutes.