mustangsally
mustangsally
Joined: Mar 29, 2011
  • Threads: 25
  • Posts: 2463
November 26th, 2013 at 2:21:38 PM permalink
Quote: JB

I basically agree. I also get 70.0234% for the 15-spot game, but 68.6915% 68.69615% for the 20-spot game.

I also get very hungry this time of year.

can your (JB) calculator be updated to include pick 20? (I am sure it can be, I could try to look at it too)

It would be interesting to see what it returns and how close it is to other calculations. (how large the error is)
I think I did this correctly
the *totals combos* and a few other combos are slightly off


That brings up what exactly is 80choose20 or C(80,20) for pick 20 calculations to start with
80! / (20! * (80-20)!)
Wolfram Alpha
http://www.wolframalpha.com/input/?i=80%21+%2F+%2820%21+*+60%21%29
3,535,316,142,212,174,320
3.53531614221217432 × 10^18

Here is what I also found
Excel 2007
3,535,316,142,212,180,000

Windows 7 calculator
3,535,316,142,212,174,320

http://en.wikipedia.org/wiki/Keno
3,535,316,142,212,174,336 to be exact
and
3,535,316,142,212,173,800.000 (to not be exact)

http://www.picalc.com/
3,535,316,142,212,172,300

http://www.mathproblems.info/gam470/games/keno/prob-keno.html
3,535,316,142,212,180,000 <<<< matches my Excel

http://www.lotto-logix.com/kenocomp.html
3,535,316,142,212,174,320 <<<< matches Windows 7 calc (looks to be the most accurate site I found)

http://betstarter.com/lottery/KenoOdds.asp
3,535,316,142,212,170,000

R program
require(Rmpfr)
chooseZ(80,20)
Big Integer ('bigz') :
3,535,316,142,212,174,320<<<< matches Windows 7 calc

Sally
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