I really need help on this question offering 10 points if anybody could help me with this with proof I'd be very thankful

Answer:
15
Step-by-step explanation:
First off we divide both sides by [tex]\frac{1}{5}[/tex] and get:
[tex]\frac{1}{5}[/tex]n÷ [tex]\frac{1}{5}[/tex]=3÷ [tex]\frac{1}{5}[/tex]
n=3×5
n=15