1. **State the problem:** We need to find which petrol is better value for money between Kieran's and Sophie's petrol, and then calculate the cost of 20 litres from the cheaper petrol station. 2. **Formula used:** To find value for money, calculate the price per litre: $$\text{Price per litre} = \frac{\text{Total price}}{\text{Litres}}$$ 3. **Calculate Kieran's price per litre:** $$\frac{16.20}{12} = 1.35$$ So, Kieran pays 1.35 per litre. 4. **Calculate Sophie's price per litre:** $$\frac{20.40}{17} = 1.2$$ So, Sophie pays 1.2 per litre. 5. **Compare prices:** Since 1.2 < 1.35, Sophie's petrol is better value for money. 6. **Calculate cost for 20 litres from Sophie's station:** $$20 \times 1.2 = 24$$ **Final answers:** - a) Sophie's petrol is better value for money. - b) 20 litres would cost 24 from Sophie's petrol station.