body { -ms-overflow-style: scrollbar; overflow-y: scroll; overscroll-behavior-y: none; } .errorContainer { background-color: #FFF; color: #0F1419; max-width: 600px; margin: 0 auto; padding: 10%; font-family: Helvetica, sans-serif; font-size: 16px; } .errorButton { margin: 3em 0; } .errorButton a { background: #1DA1F2; border-radius: 2.5em; color: white; padding: 1em 2em; text-decoration: none; } .errorButton a:hover, .errorButton a:focus { background: rgb(26, 145, 218); } .errorFooter { color: #657786; font-size: 80%; line-height: 1.5; padding: 1em 0; } .errorFooter a, .errorFooter a:visited { color: #657786; text-decoration: none; padding-right: 1em; } .errorFooter a:hover, .errorFooter a:active { text-decoration: underline; } #placeholder, #react-root { display: none !important; } body { background-color: #FFF !important; }

JavaScript is not available.

We’ve detected that JavaScript is disabled in this browser. Please enable JavaScript or switch to a supported browser to continue using twitter.com. You can see a list of supported browsers in our Help Center.

Terms of Service Privacy Policy Cookie Policy Imprint Ads info © 2023 Twitter, Inc.

Conversation

If you flip the coin and it lands heads five times in a row, you win 10,000 dollars. You flip the coin four times, and are very lucy - you get four heads in a row. You flip the fifth and final time. What are the odds it comes up heads?

over 50%
4.1%
50%
88.6%
less than 50%
7.3%

9,279 votesFinal results

63

8

91

its a fair coin u doofs

8:09 PM · Jul 3, 2022

Replying to

So you were testing basic math skills rather than the psychological phenomenon of making assumptions. Less interesting.

6

Replying to

.5 x .5 x .5 x .5 x .5

1

Replying to

Physical Coins with Physical Flipping is never fair

Persona non Greta

@rechtirrelevant

Replying to

I have thick fingers okay?

Replying to

"it's a fair coin" says the strange person offering a $10,000 prize

14

@michaelscurtis

Replying to

There is no change in odds. Every time it’s flipped it will be 50/50 for heads or tails no matter how many times heads came up in a row.

Replying to

Why should we assume that? That wasn't in the problem data, so any heuristical reasoning would include a probability, however small, of a "favorable coin"

1

11

Replying to

I presumed an imaginary coin (hence 50%); however real coins have at least three sides (they're usually cylinders).

1

Replying to

should have told me before picking, now I'm lost in calculating bayesian parameter estimation

3

Replying to

Well, of it's a fair coin then there is only one answer and the story leading up too the flip doesn't matter.