Answer:
[tex]1\frac{1}{3}[/tex] hours
Step-by-step explanation:
The first painter does [tex]\frac{1}{2}[/tex] (aka [tex]\frac{2}{4}[/tex]) the job in 1 hour.
The second painter does [tex]\frac{1}{4}[/tex] the job in 1 hour.
This means together they can do [tex]\frac{3}{4}[/tex] the job in 1 hour.
This means to do [tex]\frac{1}{4}[/tex] of the job they will need [tex]\frac{1}{3}[/tex] hours. (third of the work they do in an hour means they need a third of the time)
This means they need [tex]1\frac{1}{3}[/tex] hours to paint the room together.
