If are the probabilities of three mutually exclusive and exhaustive events, then the set of all values of p is
As 3 events are mutually exclusive and exhaustive.
∴ P(A ∪ B ∪ C) = P(A) + P(B) + P(C) = 1
⇒
⇒
⇒ 5 + 3p = 6
∴ p = 1/3
As 1/3 lies in both intervals given in option (a) and (d)
But a larger value like 100 which comes if we choose option d can make P(A) < 0 which is not possible.
∴ Option (a) is the most suitable choice here.