The 120$ repair bill included 48$ for parts and the rest for labor. what percent of the bill was for labor?

First you do 120$-48$=
1. H T U - so that you don't get confused when subtracting.
2. Layout - you need to layout your work out like this:
        
                                      H  T  U
                                       1  2  0
                                         - 4  8
                                   
                                         0   7   2  
                                   
So that mean 72% of the bill was for labour
Hope this helped you!
:)    :)   :)  :)