Answer:
18 liters
Explanation:
260 km : 65 L
72 km : ? L
Find out how far you can travel on 1 L
65/250 = 4 km
4 km : 1 L
Good. We can use this to find out how much liters we need to travel 72 km.
72 km : ? L :: 4 km : 1 L
72/4 = 18
Alas, we have our answer of 18 liters.