In a competition A, B and C are participating. The probability that A wins is twice that of B, the probability that B wins is twice that of C. Then the probability that A loses is (A, B and C are mutually exclusive and exhaustive events)
In a competition A, B and C are participating. The probability that A wins is twice that of B, the probability that B wins is twice that of C. Then the probability that A loses is (A, B and C are mutually exclusive and exhaustive events) Correct Answer 3/7
Concept:
Mutually Exhaustive Event:
- A set of events is collectively exhaustive where at least one of the events must occur.
- Example, when rolling a six-sided die, the outcomes 1, 2, 3, 4, 5, and 6 are collectively exhaustive, because they encompass the entire range of possible outcomes.
- A, B and C are mutually exclusive and exhaustive events.
- P (A ∪ B ∪ C) = P (A) + P (B) + P (C)
Calculation:
Given: A, B and C are mutually exclusive and exhaustive events.
P (A) = 2 × P (B)
∴ P (B) = P (A)/2
P (B) = 2 × P(C)
⇒ P(C) = P (B)/2
We know that P (B) = P (A)/2
∴ P(C) = P (B)/4
A, B and C are mutually exclusive and exhaustive events.
∴ P (A ∪ B ∪ C) = P (A) + P (B) + P (C)
⇒ 1 = P (A) + P (A)/2 + P (A)/4 = (4/7) × P (A)
∴ P (A) = 4/7
Then the probability that A loses is: 1 - P (A) = 1 - 4/7 = 3/7
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Feb 20, 2025