## Probability formula

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Ilovelottery
Regular Posts: 47
Joined: Sat Oct 13, 2012 10:22 am
Location: Merseyside UK

### Probability formula

Hi

Can any experts (Yes, Anastaious), tell me the formula to calculate the probability of selecting just one single number appearing? Example in a 5/50 game, if I said number 13 will appear in next draw, what is the odds? Is it 49/5? and if I then predict 2 numbers, how do I calculate the odds of BOTH appearing?

I Hope you understand my meaning!

Thanks

lottoarchitect
Posts: 1558
Joined: Tue Jan 15, 2008 5:03 pm
Location: Greece
Contact:

### Re: Probability formula

The equation is sort of complicated really, so please don't ask me to write this down! If you want to compute the odds, including any amount of correct numbers among any amount of picked numbers, GAT has an odds calculator that can compute crazy sizes up to 999. Yeah, I'm actually proud of this calculator, I never ever came across any calculator that can compute such a span of values.
To use the calculator, for your single number 13, enter the total numbers in lottery to 50, set 5 to total numbers drawn and then, how many numbers you actually pick right below. If you pick just one number, lets say 13, enter 1 to that box. In this particular game, the chance is 10% if you pick one number (13 or whatever other number) and given 5 numbers are drawn, 5/50 = 0.1 or 10% to have your picked number in there. Similarly for 2 numbers, it depends on how many numbers you actually choose and expect to have two correct in your selection. For example, if you pick only 2 numbers and expect to have both correct, chance is about 0.82% but if e.g. you pick 3 numbers and want the chance to have 2 correct this is about 2.29%. You'll find the computed percentages at the list below, you inspect the "2 correct" values indicated. If you additionally want to find out the chance to have 1 OR 2 correct out of your 2 picked, you enable the check boxes "1 correct " and "2 correct" and the percentage is indicated at the "combined" line at the bottom.

Ilovelottery
Regular Posts: 47
Joined: Sat Oct 13, 2012 10:22 am
Location: Merseyside UK

### Re: Probability formula

Thanks Lottoarchitect

I did buy GAT 2 yrs ago but wasn't what I needed and so I don't understand it really.

Yes, the 2 figures I want is 10% and 0.82%, I THINK!!!
So, lets go through it again just to be sure. If I just get to predict ONE SINGLE NUMBER ONLY from the 5 drawn numbers in 5/50 game I have 10% chance it will appear, correct? but, if I then want to predict TWO NUMBERS ONLY from the 5 drawn numbers, it goes down to a ridiculous 0.82%? No wonder bookmakers would pay you something like £600/1 for predicting 3 numbers correctly.
It's a massive difference when we can choose 5 numbers and 5 numbers are drawn.
It looks correct to me but I didn't think it was that low. Could you write the formulas down for me please (just kidding )

Thanks again.

DC_Treybil
Newbie Posts: 3
Joined: Sun May 15, 2016 2:11 am

### Re: Probability formula

I'm assuming that 5/50 means there are 50 possible values and 5 draws.

If this is the concept of the drawing you have in mind, there are 2,118,760 possible combinations.

Assuming you're drawing exactly 5 balls, the odds of getting 1 ball are 0.351608959957711 (or 2.844068593 : 1)

Again, assuming you're drawing exactly 5 balls, the odds of getting 2 balls are 0.0669731352300402 (or 14.931360113 : 1)

The odds of getting 3 balls are 0.0046725443183749 (or 214.016161616 : 1)

The odds of getting 4 balls are 0.000106194189053975 (or 9,416.711111111 : 1)

The odds of getting 5 balls are 0.000000471974173573222 (or 2,118,760 : 1)

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