Speed, time and distance
How long does the trip take? How fast did they drive? If you know two of speed, time and distance, you can find the third.
Your numbers
Answer
Time
1 h 30 min
In hours
1.5h
In minutes
90min
How to work it out
- 1t = s / v = 120 km / 80 km/t = 1.5 t
- 20.5 t · 60 = 30 min
The formula
s = v · t
Distance = speed times time.
v = s / t · t = s / v
Keep the units consistent: km/h goes with km and hours. 30 minutes is 0.5 hours — not 0.3.