Answer:
1 and 1/4 liters of paint are needed for one door
Explanation:
You can eliminate each answer choice out. For '4/5 liters' you know that if that amount was used, it wouldn't be reasonable since it would mean that the more was used for the other 3/5 door. 3 and 1.5 would be too much since it is over 2 liters. 2 liters wouldn't be logical since you paint 1 and 3/5 of a door and you only used 2 liters, no more or no less, basically what would you use for the other 3/5 door if this was the answer.
Hope this helps!