Functional Skills: Speed

Example 1: Calculating Speed

A car travels 30 km in 48 minutes. Calculate the average speed of the journey in km/h.

[2 marks]

First convert 48 minutes into hours: 48 minutes =\dfrac{48}{60} hours =0.8 hours

Then calculate the average speed: \text{Speed} = \dfrac{\text{Distance}}{\text{Time}}=\dfrac{30}{0.8}=37.5 km/h

Example 2: Calculating Distance

A cyclist travels at an average speed of 14 mph for 25 minutes. Calculate how far the cyclist travelled, give your answer to 2 decimal places.

[2 marks]

Using the speed, distance and time triangle we can see that:  distance = speed \times time.

So the distance travelled by the cyclist =14\times \dfrac{25}{60}=5.83 miles

Note: You often need to convert minutes into hours.

Example 3: Calculating Time

A plane is going from Manchester to Madrid, which is a 1292 mile journey.

The plane travels at an average speed of 516.8 mph, calculate the time taken for this flight, giving your answer in hours and minutes.

[2 marks]

Using the speed, distance and time triangle we can see that:  \text{time} = \dfrac{\text{distance}}{\text{speed}}

So the time taken for the journey =\dfrac{1292}{516.8}=2.5 hours =2 hours and 30 minutes