There's a probability question I saw on the web that looks innocent enough, unless you pay attention to the wording:(adsbygoogle = window.adsbygoogle || []).push({});

I have two dice.

If i roll them until i get a double, which is the most likely roll to get a double on?

The answer given is below:

The first roll is the most likely.

Heres why

First Roll:

1/6 Chance to get Double. 5/6 Chance to not get double

Total Chance: 1/6

Second Roll

5/6 Chance to Reach This Stage

1/6 Chance to get double

Total Chance = 5/36

Third Roll

25/36 Chance to Reach This Stage

1/6 Chance to get double

Total Chance = 25/216

You get the idea. This carries on.

The answer makes sense to me, but probably due to the wording of the question, I am still slightly inclined to think that the answer is "equally likely". Note that the person will stop rolling the dice when he hits a double.

What do you think?

**Physics Forums - The Fusion of Science and Community**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Dice problem that I can't fully get my head around

Loading...

Similar Threads - Dice problem can't | Date |
---|---|

B Simultaneous roll of Non Transitive Dice | Oct 16, 2017 |

Zero-modified geometric dice problem | Dec 7, 2011 |

Puzzling roll X dice, choose Y highest problem | Jul 24, 2010 |

Sum of dice Problem | Nov 28, 2006 |

Dice Game Problem (Hard) | Apr 22, 2005 |

**Physics Forums - The Fusion of Science and Community**