Brain Teasers & Mental Math
Probability / EV: a coin is biased so P(heads) = 0.6. You win $10 on heads and lose $5 on tails. What is the expected value per flip?
Model answer
+$4 per flip.
EV = (0.6)(+$10) + (0.4)(−$5) = $6 − $2 = +$4.
Method: multiply each outcome's payoff by its probability and…
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