Facing Marilyse...

Marilyse Legahuana has 3 coins, one with two 'tails' faces, one with two 'heads' faces,
and a usual 'heads/tails' one. She take one of these coins from her pocket and put it down onto the ground.
Aha, tails.

Question : what is the probability that the other face is heads ?

(Thanks to E.C. !)


Back to the enigmas