1. **State the problem:** John hired a car for 8 days and drove 850 kilometres. We need to find the total cost of hiring the car. 2. **Formula used:** The total cost is calculated by adding the daily hire cost and the cost per kilometre driven. $$\text{Total Cost} = (\text{Daily Rate} \times \text{Number of Days}) + (\text{Cost per km} \times \text{Kilometres Driven})$$ 3. **Given values:** - Daily Rate = 70 - Number of Days = 8 - Cost per kilometre = 0.40 - Kilometres Driven = 850 4. **Calculate daily hire cost:** $$70 \times 8 = 560$$ 5. **Calculate cost for kilometres driven:** $$0.40 \times 850 = 340$$ 6. **Calculate total cost:** $$560 + 340 = 900$$ 7. **Answer:** The total cost of hiring the car is 900.