Question
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?
Solution
Let R be the event of drawing the red marble.
Let E_{A}, E_{B}, and E_{C} respectively denote the events of selecting the box A, B, and C.
Total number of marbles = 40
Number of red marbles = 15
`:.P(R) = 15/40 =3/8`
Probability of drawing the red marble from box A is given by P (E_{A}|R).
Probability that the red marble is from box B is P (E_{B}|R).
Probability that the red marble is from box C is P (E_{C}|R).
Is there an error in this question or solution?
Solution Suppose We Have Four Boxes. A, B, C and D Containing Coloured Marbles as Given Below: 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? Concept: Conditional Probability.