A game consists of randomly choosing a bag (labelled 1, 2 or 3) out of a choice of 100, and then again randomly, picking a ball (red or black) from it.
Each bag has the same total number of balls (10).
Bag options
Ball options
a) Complete the tree diagram.
0.6 Red
b) Work out the probability that a player
will select a red ball.
0.4 Black
0.35
+
0.2
Red
0.45
2.
0.8
Black
c) The same player is going to play the
game 200 times consecutively.
How many black balls should he
expect to pick?
0.7
Red
+
3
0.3
Black