Answer:
[tex]\frac{9}{2}[/tex]
Step-by-step explanation:
cup of mayo used for 5 servings = [tex]\frac{3}{4}[/tex]
cup of mayo used for 1 servings = [tex]\frac{3}{4}*\frac{1}{5}=\frac{3}{20}[/tex]
cup of mayo needed for 30 servings= [tex]\frac{3}{20}*30=\frac{9}{2}[/tex]