1. Three Bags, \(A , B\) and \(C\), each contain 1 red marble and some green marbles.

\begin{displayquote} Bag \(A\) contains 1 red marble and 9 green marbles only
Bag \(B\) contains 1 red marble and 4 green marbles only
Bag \(C\) contains 1 red marble and 2 green marbles only \end{displayquote} Sasha selects at random one marble from \(\operatorname { Bag } A\).
If he selects a red marble, he stops selecting.
If the marble is green, he continues by selecting at random one marble from Bag \(B\).
If he selects a red marble, he stops selecting.
If the marble is green, he continues by selecting at random one marble from Bag \(C\).

1. Draw a tree diagram to represent this information.
2. Find the probability that Sasha selects 3 green marbles.
3. Find the probability that Sasha selects at least 1 marble of each colour.
4. Given that Sasha selects a red marble, find the probability that he selects it from Bag \(B\).