Thread Rating:

lirious
lirious
  • Threads: 1
  • Posts: 1
Joined: Jan 5, 2012
January 5th, 2012 at 12:31:48 PM permalink
Can someone please tell me what the probability is of rolling 5 six sided dice (all at once) and not getting a least one 1 or 5? What about when rolling 4?
How is this different than the odds given the same scenario?

Thank you in advance for your kind consideration of this newbie.

Darrin
EdCollins
EdCollins
  • Threads: 20
  • Posts: 1739
Joined: Oct 21, 2011
January 5th, 2012 at 9:09:10 PM permalink
Hi Darrin,

When rolling five dice, the probability of NOT getting at least one 1 or one 5 is small... .13168 (About 13.17%)
(4/6)^5

In other words, if you are playing "Oh Shit" or "Farkle" or whatever name that dice game is going under these days, there is about an 87% chance you will roll that much needed 1 or 5, when rolling five dice.

When rolling just four dice, obviously not rolling at least one 1 or one 5 will happen more often. The probability jumps up to .19753.... about 19.75%.

(4/6)^4


If you want to know the odds, it's easy. A 20% chance, for example, will happen 1 time in 5. So the odds are 4 to 1 in your favor. (Or against you, depending upon how you look at it.)

A 13% chance will happen about 1 time in about 7.6 attempts. So the odds are 6.6 to 1 in your favor. (Or against you, depending upon what you want.)

Hope this helps.
NowTheSerpent
NowTheSerpent
  • Threads: 15
  • Posts: 417
Joined: Sep 30, 2011
January 6th, 2012 at 4:40:11 AM permalink
Why does Farkle make it '1' or '5' instead of '1' or '6'?
Dween
Dween
  • Threads: 66
  • Posts: 339
Joined: Jan 24, 2010
January 6th, 2012 at 5:44:53 AM permalink
There are lots of variants of this game out there, including branded ones like "Farkle", "Risk and Roll 2000", "Cosmic Wimpout", and surely others.

In general, starting a turn with 5 (or 6) dice, you must roll a 1 (worth 100 points), a 5 (worth 50 points), or a three of a kind (worth 100 x value, except 1's are 1000). Some versions allow for other special combos (1-6 straight; 3 pair). You also must set aside the dice you wish to score, and then decide if you want to roll again. Scoring with all 6 dice usually allows you to reroll all 6 dice again to increase score.

Also depending on the version, you may have to score a certain amount of points before being allowed to stop.

So while the odds of getting a 1 or 5 are nice to know offhand, when you have 3 or more dice, getting triplets can increase the odds of scoring.
-Dween!
  • Jump to: