#### zulu

##### New Member
in lottery, there are 20 balls, only 8 comes out. what are the chances that one ball didn t go out for 19 times in a row? please help

#### katxt

##### Active Member
One particular ball did not appear? or some ball did not appear?

#### zulu

##### New Member
One particular ball did not appear? or some ball did not appear?
the same ball didnt appear 19 times in a row..there are 20 balls and lets say ball number 5 didnt appear 19 times in a row

#### katxt

##### Active Member
OK. So what is the probability that 5 didn't appear in the first draw?

#### katxt

##### Active Member
Right. 12 chances of a miss out of 20 = 60% or 0.6.
The probability of 2 misses in a row is 60% of 60% = 0.36 = 0.6^2. Carry on the pattern.

#### zulu

##### New Member
I dont know how to calculate that long, can you do it for me,please

#### katxt

##### Active Member
Do have a calculator? or find one on line.

#### zulu

##### New Member
I dont know how to find 60% of every number i get 19 times in a row..Can you please do it for me

#### katxt

##### Active Member
No. What you need is 0.6^19. Google it. kat

#### zulu

##### New Member
0.00006093597 ?
So that means it will apear 6 times in 100 000 draws?

#### zulu

##### New Member
well, you could told me solution right away thank you

#### Dason

well, you could told me solution right away thank you
If that's your attitude you gotta pay.

Also keep in mind that is the probability *if* you specified a certain number that you didn't want to show up at all. It's a slightly different calculation if all you want is the probability that after 19 draws there exists at least one number that wasn't picked.

#### zulu

##### New Member
So I guess if I want to calculate on the same lottery(8/20) that the same ball will appear 11 times in a row i will 0.4^11 =0.00004194304 which means 4 times in 100 000 draws? am I right?

#### zulu

##### New Member
If that's your attitude you gotta pay.

Also keep in mind that is the probability *if* you specified a certain number that you didn't want to show up at all. It's a slightly different calculation if all you want is the probability that after 19 draws there exists at least one number that wasn't picked.
so it wont be the same result like certain number? what is than calculation for at least one number that wasnt picked 19 times in a row? it s definetly lower number than 6 times in 100 000