James and Peter cycled along the same 50 km route - Edexcel - GCSE Maths - Question 9 - 2017 - Paper 1

Using the speed calculated, we find the time taken by James to cycle 15 km:

$\text{Time} = \frac{\text{Distance}}{\text{Speed}} = \frac{15 \text{ km}}{20 \text{ km/h}} = 0.75 \text{ hours} = 45 \text{ minutes}$

Since Peter started 5 minutes after James, his start time is:

$45 \text{ minutes} - 5 \text{ minutes} = 40 \text{ minutes}$

This means Peter took 40 minutes to reach the 15 km mark.

We can now find Peter's speed using the distance he traveled and the time taken:

$\text{Peter's Speed} = \frac{15 \text{ km}}{\frac{40}{60} \text{ hours}} = \frac{15 \text{ km}}{\frac{2}{3} \text{ hours}} = 22.5 \text{ km/h}$