A car mechanic has a tin containing 5 litres of engine oil - OCR - GCSE Maths - Question 14 - 2021 - Paper 1

The tin contains 5 litres of oil. To convert this into millilitres:

$5 ext{ litres} = 5000 ext{ ml}$

Next, we need to find out what 80% of the total oil amount is:

$80\% \text{ of } 5000 ext{ ml} = 0.8 \times 5000 = 4000 ext{ ml}$

Now we compare the total amount of oil used after 9 weeks to 80% of the tin:

• Total oil used: 4050 ml
• 80% of tin: 4000 ml

Since 4050 ml > 4000 ml, the car mechanic's claim is correct.