ExpertMedium3 marksStructured
AQA GCSE · Question 17 · Ratio Proportion and Rates of Change
A car travels 4 miles in 5 minutes. Work out the average speed in miles per hour.
A car travels 4 miles in 5 minutes. Work out the average speed in miles per hour.
How to approach this question
The car travels 4 miles in 5 minutes. We need to find out how many miles it would travel in 1 hour (60 minutes).
1. **Find how many 5-minute intervals are in an hour:**
60 minutes ÷ 5 minutes = 12.
2. **Calculate the total distance travelled in that many intervals:**
The car travels 4 miles in each 5-minute interval.
Total distance in 1 hour = 12 intervals × 4 miles/interval = 48 miles.
3. **State the speed:**
The car travels 48 miles in 1 hour, so the speed is 48 mph.
Full Answer
48 mph
Speed is a measure of distance travelled over a certain time. The required unit is miles per hour (mph), which means "miles travelled in one hour".
We are given that the car travels 4 miles in 5 minutes.
Our goal is to find the distance it would travel in 1 hour.
First, let's note that 1 hour = 60 minutes.
We need to scale up the time from 5 minutes to 60 minutes. To do this, we find how many times 5 minutes fits into 60 minutes.
60 ÷ 5 = 12.
So, 1 hour is 12 times longer than 5 minutes.
Assuming a constant speed, the car will travel 12 times further in 1 hour than it does in 5 minutes.
Distance in 1 hour = 12 × (distance in 5 minutes)
Distance in 1 hour = 12 × 4 miles = 48 miles.
Since the car travels 48 miles in 1 hour, its average speed is 48 mph.
Common mistakes
✗ Incorrectly calculating how many 5-minute intervals are in an hour (e.g., 60 ÷ 4 = 15).\n✗ Trying to divide 4 by 5 and getting confused with decimals.\n✗ Multiplying 60 by 4.
Practice the full AQA GCSE Maths Foundation Tier Paper 1 Non-Calculator
41 questions · hints · full answers · grading