Suppose you have two coins which appear identical in your pocket. You know that one is fair and one is 2-headed. If you take one out, toss it and get a head, what is the probability that it was a fair coin?
Let E1= event that fair coin is drawn
E2 = event that two headed coin is drawn
E= event that tossed coin get a head
∴
Using Bayes’ theorem, we have