Answer: 12.5 litres
Explanation:
The SUV takes 2.5 litres for every 20 km driven.
The trip to work is 20 km which means that going to work costs Marie's father 2.5 litres every day in fuel.
In a week, there are 5 working days.
The amount of fuel used per week is therefore:
= 2.5 * 5
= 12.5 litres