How long does it take to travel 120 km at 80 km/h?

1 h 30 min. 120 ÷ 80 = 1.5 hours = 1 h 30 min.

11+ Maths · Topic explained

Speed, distance and time

A car travels at 60 km/h. How far does it go in 3 hours?

The big idea

Speed is how far you go each hour: distance = speed × time.

Picture it

60 km/h means 60 km in every hour: 3 hours, 3 lots of 60 = 180 km.

Key words

speed: How far you travel in each unit of time.
km/h: Kilometres per hour: kilometres travelled in 1 hour.
the triangle: D on top, S and T below: cover the one you want.

Worked examples

1Warm-up
A cyclist rides at 20 km/h for 2 hours. How far does she go?
- Distance = speed × time
- 20 × 2 = 40 km
211+ standard
A train travels 150 km in 2½ hours. What is its average speed?
- Speed = distance ÷ time
- 150 ÷ 2.5 = 60 km/h
- Check: 60 × 2½ = 150 ✓
311+ standard
How long does it take to drive 45 km at 30 km/h?
- Time = distance ÷ speed
- 45 ÷ 30 = 1½ hours = 1 h 30 min
411+ standard
A car travels at 48 km/h for 20 minutes. How far does it go?
- 20 minutes = ⅓ of an hour
- ⅓ of 48 = 16 km

The common mistake

The mistake

1 hour 30 minutes = 1.3 hours.

Instead

30 minutes is half an hour, so it's 1.5 hours.

Why: There are 60 minutes in an hour, not 100: 30 minutes is 30/60 = 0.5 of an hour.

Where it comes up in the 11+

Find the distance, speed or time, often with minutes to turn into fractions of an hour.

The video

Video coming soon

We're making a short video that explains speed, distance and time step by step. Until then, everything it covers is on this page.

Free printable