My friend gave me qusetion to solv and its very difficult for me.

John is three times older than Bob. In P years John will be twice older than Bob will be InQ years later..If X denotes John's age, which of the following represents John's age compared to Bobs?

Correct answer
is

X+P/2 = X/3 +P+ Q


How do you get this answer


Johns age = 3b
jOHNS age + p=

HELP!!!