To solve this problem you must keep on mind the following information:
The problem says that Homeroom 101 can use a half of display artwork (which is [tex]\frac{1}{2}[/tex]) and they use [tex]\frac{3}{5}[/tex]. Therefore, you only need to multiply both fractions, as following:
[tex](\frac{1}{2} )(\frac{3}{5} )=\frac{3}{10}[/tex]
Therefore, as you can see, the answer is: [tex]\frac{3}{10}[/tex] of the bulletin board is used to display Homeroom 101’s artwork.