1. **Stating the Problem:** We want to find out which petrol option offers better value for money and then calculate the cost of 30 litres from the cheaper option. 2. **Calculate price per litre for Lois:** \[\text{Price per litre}_{Lois} = \frac{17.40}{12} = 1.45 \text{ (pounds per litre)}\] 3. **Calculate price per litre for Alexander:** \[\text{Price per litre}_{Alexander} = \frac{22.80}{19} = 1.20 \text{ (pounds per litre)}\] 4. **Compare values:** Alexander's petrol costs 1.20 per litre, Lois's costs 1.45 per litre, so Alexander's petrol is better value for money. 5. **Calculate cost for 30 litres of Alexander's petrol:** \[\text{Cost} = 30 \times 1.20 = 36.00 \text{ pounds}\] **Final Answer:** - a) Alexander's petrol is better value for money. - b) 30 litres from Alexander's petrol station would cost 36.00 pounds.