Answer:
133 windows
Explanation:
First, you would want to find how many windows he can clean in 1 hour.
You know that 38 windows = 2 hours.
To do this, divide both sides by 2 (to get 1 hour). You will get 19 windows = 1 hour.
Now to find 7 hours, multiply both sides of 19 windows = 1 hour by 7 (to get 7 hours). You will get 133 windows cleaned in 7 hours.