a thoughtful web.
Good ideas and conversation. No ads, no tracking.   Login or Take a Tour!
comment
wasoxygen  ·  3147 days ago  ·  link  ·    ·  parent  ·  post: The fake coin probability problem

You have in your pocket two coins. One is a normal fair coin, and one is a fake coin that has "heads" on both sides.

You reach into your pocket and take one of them at random. You toss it one, two, three times. It comes up heads, heads, then tails.

Then mike says "No, that doesn't count. Start over." You put the coin back in your pocket.

You have in your pocket two coins. One is a normal fair coin, and one is a fake coin that has "heads" on both sides.

You reach into your pocket and take one of them at random. You toss it one, two, three times. On each flip, the coin comes up heads.

What is the probability that the coin will land heads on the next flip?