Okay this is how I would figure this out:
I would take 9 divided by 3 and get 3, so he can tile abut 3 square ft. in 15 minutes.
Then, I would multiply 3 by 4 because there are 4 15 in an hour. I would get 12.
So it takes Jakob 1 hour to tile 12 square feet.
Your answer is: He can tile about 12 square feet per hour.
Hope this helped :)
