An Engineer entered the room. He took the bucket of sand and sprayed it on the fire and the fire was gone.
In the same situation, a Research Scientist entered the room. He took the bucket of sand and made a ring of sand around the fire and sat in front of the fire and watched the fire.
Now a Mathematician enters the same room with the same situation. He sees that there is a fire. He also sees that there is a bucket of sand. He calculates and concludes that a solution exists and leaves the room.