Answer:they need to buy 27 boxes of plates.
Step-by-step explanation:I do not like expaining things.
THIS IS THE CORRECT ANSWER I GOT WHEN SOLVING ON MY IPHONE
4-x I know this because my teacher just went over this problem
Answer:

<em>hope</em><em> </em><em>this</em><em> </em><em>helps</em><em>.</em><em>.</em><em>.</em><em>.</em>