Answer:
1005.68 litres
Step-by-step explanation:
Steps to answering this question
1 gallon = 3.78541 litres
13.6 gallons x 3.78541 = 51.48 litres
1 mile = 1.60934 km
321.7 miles x 1.60934 = 517.72 km
Litre needed per kilometer = 517.72 km / 51.48 = 10.06
Litres needed for 100 km = 100km x 10.06 = 1005.68 litres