how many windows ?

Question

the office building where leon's dad works has two more windows on the first floor and two times as many windows on the second floor as on the third floor. there are nine windows on the third floor. how many windows are there in the building?

Answer 1

Let's start from the top, since we have a known number of windows there.

If there are nine windows on the top floor, and the second floor two times as many windows than the third floor:

9 windows x 2 windows = 19 windows on the second floor.

If there are nine windows on the top floor, and the first floor has two more windows than the third floor:

9 windows + 2 windows = 11 windows on the first floor.

Now we add all the windows on each floor together:

11 windows + 19 windows + 9 windows = 39 windows