please need help I will be MARKING as BRIANILIST. thank you so much.

Answer:
C. 7
Step-by-step explanation:
Custodian has = [tex]5 \frac{1}{4} gallons[/tex]
Ever bookcase needs = [tex]\frac{3}{4} gallons[/tex]
We'll just divide them
Bookcases to be painted = [tex]5\frac{1}{4} / \frac{3}{4}[/tex]
= [tex]\frac{21}{4}* \frac{4}{3}[/tex]
= [tex]\frac{21}{3}[/tex]
= 7