A high speed train travels a distance of 487 km in 3 hours - Edexcel - GCSE Maths - Question 19 - 2018 - Paper 3

Similarly, the lower bound for the distance is:

Lower bound of distance = 486.5 km

The time is measured correct to the nearest minute. Thus, the time in minutes for 3 hours is:

Time = 3 imes 60 = 180 minutes

Upper bound of time = 180.5 minutes

The lower bound for the time is:

Lower bound of time = 179.5 minutes

To find the average speed, we use the formula:

Average Speed = ( \frac{\text{Distance}}{\text{Time}} )

Calculating the upper average speed:

$\text{Upper average speed} = \frac{487.5 \text{ km}}{179.5 \text{ min}} \approx 2.71 \text{ km/min}$

Calculating the lower average speed:

$\text{Lower average speed} = \frac{486.5 \text{ km}}{180.5 \text{ min}} \approx 2.70 \text{ km/min}$

Thus, the average speed of the train, considering bounds, is approximately:

Average Speed = 2.7 km/min to 2 significant figures.