Q. 12 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 C?


Answers (1)
S seema garhwal

Let R be event of drawing red marble.

Let E_A,E_B,E_C  respectivly denote event of selecting box A,B,C.

Total marbles = 40

Red marbles =15


Probability of drawing red marble from box C  is P(E_C|R)

                          P(E_C|R)=\frac{P(E_C\cap R)}{P(R)}