Give the step-by-step reasoning process and then the final answer. Lucille is painting her room. Two of her walls are 3 meters wide and 2 meters tall. The third wall is 5 meters wide and 2 meters tall. The final wall is 4 meters wide and 2 meters tall. If each can of paint covers 2 square meters, how many cans of paint does Lucille need?
For the first set of walls, each wall covers 3 meters wide * 2 meters tall = 6 square meters. There are two of these walls, so this becomes a total of 6 meters * 2 walls = 12 square meters. The third wall covers 5 meters wide * 2 meters tall = 10 square meters. The final wall covers 4 meters wide * 2 meters tall = 8 square meters. So in total, the paint needs to cover 12 + 10 + 8 = 30 metres. Since each can covers 2 meters, Lucille needs 30 meters / 2 = 15 cans of paint.
The final answer: 15.