In a seven-match series between Australia and South Africa, the probability of South Africa...
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In a seven-match series between Australia and South Africa, the probability of South Africa winning any individual match is $3/4$. What is the probability of South Africa winning back-to-back matches?
Show answer & explanation
The probability of South Africa winning any two consecutive matches is calculated by multiplying the probability of winning each individual match: P(two consecutive wins) = (3/4) × (3/4) = 9/16. This represents the likelihood of South Africa winning at least one pair of back-to-back matches in the seven-match series.
Step-by-step Derivation:
Step 1: Identify the probability of South Africa winning a single match: P(win) = 3/4
Step 2: For back-to-back (consecutive) wins, we need two consecutive victories.
Step 3: Assuming independence of matches, the probability of winning two consecutive matches is:
P(back-to-back wins) = P(win on match i) × P(win on match i+1)
P(back-to-back wins) = (3/4) × (3/4) = 9/16
Step 4: Verify: 9/16 ≈ 0.5625, which is reasonable since (3/4)² = 0.5625 ✓
Note: The question asks for the probability of back-to-back matches (any consecutive pair), not the probability of at least one such pair occurring in all seven matches. The straightforward interpretation is the probability of two consecutive wins = 9/16.