Heads given at least one head
A fair coin is flipped three times. Given that at least one flip came up heads, what is the expected number of heads? (to 4 decimals)
Show hints (2)+
- Condition: throw out the all-tails outcome, so the denominator is 7/8, not 1.
- Numerator = unconditional total heads = 1.5 (the dropped outcome had 0 heads); divide by 7/8.
Answer
Reveal answer →Final answer
1.7143 (± 0.001)
Want the full step-by-step worked solution? It's part of Premium - along with a worked solution for every question in the bank.
Asked at: Game-Based Aptitude, Options Market-Making