MEASURES AND TIME

Compound Measures

Learn the reliable method for compound measures, then apply it to 11+ exam-style questions.

1 · WHAT YOU NEED TO KNOW

The idea

Compound measures connect two quantities, such as distance and time.

Picture itConnect the number to its unit and scale
2 · THE METHOD

Follow these steps

  1. Identify the two quantities and the relationship between them.
  2. Use the relevant formula, such as speed = distance ÷ time.
  3. Convert units before calculating and state the compound unit.
3 · WORKED EXAMPLES

See the method in action

Example 1

Use the journey information shown. How far does the coach travel?

65 km/h2 h 30 min
  1. 30 minutes is 0.5 hours, so the time is 2.5 hours.
  2. Distance = speed × time = 65 × 2.5 = 162.5 km.
Answer: 162.5 km
Example 2

A pump transfers 9 litres in 45 minutes. At the same rate, how many litres does it transfer in 60 minutes?

  1. 45 minutes is 0.75 hour.
  2. The hourly amount is 9 ÷ 0.75 = 12 litres.
Answer: 12 litres
4 · ELEVENSPRINT TIP

A useful shortcut

Convert units before calculating and state the compound unit.

5 · COMMON MISTAKES

Watch out for these

6 · TRY IT YOURSELF

Three fresh questions

Ready to check the method? You will get three fresh, validated questions.