Example

During a recent trip, Robert drove 483 kilometres in 7 hours.

• What was his average speed during the trip?
• If he drove at the same average speed, what distance would he cover in 10 hours?

Example of solution:

The average speed is the number of kilometres covered by a unit of time, which in this case is one hour. Here, Robert drove a distance of 483 km in 7 hours. His speed, in kilometres per hour (km/h), can be obtained by examining the ratio:

[latex]\dfrac{\textrm{distance}}{\textrm{duration}}=\dfrac{483}{7}[/latex].

• Because 483÷ 7 = 69, his average speed was 69 km/h.
• The distance covered in 10 hours can be found by considering the proportion: [latex]\dfrac {483} {7}=\dfrac {x} {10}[/latex]. Therefore, we find: [latex]x = 69 × 10 = 690[/latex]. Robert would drive 690 km in 10 hours.