Suppose we have four boxes A, B, C and D containing coloured marbles as given below:
|
Box |
Marble Colour |
||
|
Red |
White |
Black |
|
|
A |
1 |
6 |
3 |
|
B |
6 |
2 |
2 |
|
C |
8 |
1 |
1 |
|
D |
0 |
6 |
4 |
One of the boxes has been selected at random and a single marble is drawn from it. If the marble is red. what is the probability that it was drawn from box A? box B? box C?
Let E, E1, E2, E3 and E4 be the events as defined below:
E : ‘ball drawn is red’, E1 : ‘box A is selected’, E2: ‘box B is selected’,
E3 : ‘box C is selected ‘ and E4 : ‘box D is selected’,
and 
and 
P(ball is drawn from box A) = 
P(ball is drawn from box C) = 
and P(ball is drawn from box A) = 
