Tom liked to draw and he wanted to design houses when he grew up. One day he drew a picture of the front of a house that had 3 floors. He used 3 different
shapes for the windows. He used rectangles, triangles and pentagons. There
were twice as many triangles as pentagons and twice as many rectangles as
triangles and pentagons combined. There were a total of 18 windows on the
front of the house. How many rectangles were there? How many pentagons
were there? How many triangles were there?