Question #c856b

2 Answers
Apr 16, 2017

There are 16 windows on the first floor.

Explanation:

Let xx equal the number of windows on the second floor.

Thus, the number of windows on the first floor is equal to x-2x2, and the number of windows on the third floor is x/2x2.

Given that there are 9 windows on the third floor, we set x/2x2 equal to 9 and find that:
x/2=9x2=9
x=18x=18

There are thus 18 windows on the second floor, but there are two fewer on the first floor. Therefore the first floor has 16 windows.

Apr 16, 2017

1616 windows on the first floor.

Explanation:

We have to define a variable first to be able to make an equation.

The first floor has the smallest number of windows, so,
let the number of first floor windows be xx.

Write the windows on the other floors in terms of xx

The second floor has two more: " ":.x+2 windows

The third floor has half as many as the second floor:

The number of windows on the the third floor = (x+2)/2

But there are 9 windows on the third floor.
:. (x+2)/2 = 9" "larr solve for x

x+2 = 2xx9

x =18-2

x = 16

16 windows on the first floor.