Answer:
[tex]\frac{4}{3}[/tex]p -5 is the nieces age.
Step-by-step explanation:
Jacob is 4p years old.
[tex]\frac{1}{3}[/tex] Jacobs age is [tex]\frac{1}{3}[/tex] * 4p = [tex]\frac{4}{3}[/tex]p
His niece is 5 years younger than this or
Niece's age = [tex]\frac{4}{3}[/tex]p -5 years old
