1. **Problem (a):** Sundip buys 30 litres of fuel at £1.50 per litre and pays the exact amount using three bank notes of £5, £10, £20, or £50. 2. Calculate the total cost of fuel: $$30 \times 1.50 = 45$$ 3. Sundip pays £45 exactly with three bank notes. Possible bank notes are £5, £10, £20, and £50. 4. Find combinations of three bank notes that sum to £45: - £20 + £20 + £5 = £45 - £10 + £10 + £25 (not valid since £25 note doesn't exist) - £10 + £20 + £15 (not valid) Only valid combination: **£20, £20, and £5** --- 5. **Problem (b):** Sundip's car uses 1 litre every 16 km. 6. Initially, car has 50 litres. It uses $\frac{7}{10}$ of this fuel: $$50 \times \frac{7}{10} = 35$$ litres used. 7. Distance travelled in kilometres: $$35 \times 16 = 560$$ km 8. Convert kilometres to miles using $5$ miles = $8$ kilometres: $$\text{Miles} = \frac{560 \times 5}{8} = 350$$ miles **Final answers:** (a) The three bank notes are £20, £20, and £5. (b) Sundip travels **350 miles** on this journey.