Answer: £24.86
Step-by-step explanation
litres = pounds £
198 223.74
divide both sides by 198 to find how much 1 litre costs
1 = 1.13
multiply both sides by 22
22 24.86
(This is direct proportion since as litres decrease, the price decreases.
It would be different method if it was indirect proportion (where one thing goes up, another goes down )