# Thread: Probability Formula? Thanks: 0 Likes: 0

1. ## Probability Formula?

There are 3 balls in a bag, one red, two blue.

Therefore, there is a 33.33% (Cell A1) chance of picking the red ball, and a 66.66% (Cell A2) of picking a blue ball.

Would there be a formula to calculate the probability in a 'Best of X' race?

So for instance, what would be the probability of picking 2 red balls, before 2 blue balls? (Best of 3)

or the probability of picking 7 red balls, before 7 blue balls? (Best of 13)

This question always assumes there are always 3 balls are always in the bag. So it's always a 33.33/66.66% chance.

Thanks!  Reply With Quote

2. ## Re: Probabilty Formula?

You would be able to achieve this through using .... =Binomdist or a combination of these

will play with it now  Reply With Quote

3. ## Re: Probabilty Formula?

see if this is what you need ...

Place the headings "best of", "minimum # of success needed", "# combinations", "probability" in cells F24, G24, H24, I24

in F25 enter ... 3
in G25 enter ... =ROUNDDOWN(F25/2+1,0)
in H25 enter ... =COMBIN(F25,G25)
in I25 enter ... =BINOMDIST(G25,F25,1/3,FALSE)

in F26 enter ... =F25+1 and drag down as far as needed

drag down cells G25, H25 and I25 as far as needed

you should have the correct probabilities in decimal form

Kind regards

Chris  Reply With Quote

4. ## Re: Probabilty Formula?

Was that what you wanted ?

Kind regards,

Chris  Reply With Quote

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