Acleaning crew can clean 5 offices in 6hours. how many offices can they clean in 12 hours

Set up a proportion like this
   =
 
So your proportion would be:
 
We put x for offices because they are asking for the number o offices a crew can paint in 12 hours, and also we don't know the number of offices they can paint in 12 hours
       so we cross multiply and we get
     6x=60, we got 60 by multiplying 12 and 5
Now we divide both sides by 6 and we get
  x=10
S the crew can paint 10 offices in 12 hours.