Question
A letter is known to have come from either TATANAGAR or CALCUTTA. On the envelope, just two consecutive letters, TA are visible. Find the probability that the letter has come from CALCUTTA.
Solution
Let E1 be the event that the letter has come from TATANAGAR and E2 be the event that it has come from CALCUTTA.
Let A denote the event that the two consecutive letters on the envelope are TA.
∴ E1 and E2 are mutually exclusive and exhaustive events
P(A/E1) = Probability that the consecutive letters TA visible on the envelope belong to TATANAGAR.
Similarly P(A/E2) = Probability that the consecutive letters TA are visible belong to CALCUTTA
