Practice question · Numerical answer
A fair coin is flipped three times. Compute the probability of getting at least one head.
Hints
- The complement of 'at least one head' is 'no heads at all'.
- The probability of three tails in a row is one eighth.
Show the answer
0.875 (answers within ±0.005 count)
Why
P(no heads) = = 1/8, so P(at least one) = 1 - 1/8 = 7/8 = 0.875. 'At least one' problems are almost always easier through the complement, enumerating the seven favourable outcomes directly is far more work.
Practise Introduction to Probability
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