Three identical bags each contain $10$ balls, whose colour distributions are:

Bag I: $3$ Red, $2$ Blue, $5$ Green
Bag II: $4$ Red, $3$ Blue, $3$ Green
Bag III: $5$ Red, $1$ Blue, $4$ Green

A person chooses a bag at random and takes out a ball. If the ball is Red, the probability that it is from Bag I is $p$, and if the ball is Green, the probability that it is from Bag III is $q$. Then the value of $\dfrac{1}{p} + \dfrac{1}{q}$ is: