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A fair coin is tossed three times. The probability of getting at least one head is:
A3/8 of trials
B7/8 of trials
C5/8 of trials
D1/2 of trials
Answer & Solution
Correct answer: B. 7/8 of trials
1. At least one head is the complement of getting no head at all.
2. P(no head) = P(TTT) = 1/8 among the 8 equally likely outcomes.
3. P(at least one head) = 1 - 1/8 = 7/8.
_Source: NCERT Class 11 Mathematics, Ch 14 'Probability' (kemh114)_
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