# Simple Probability Question

#### cmarkos111

##### New Member
Hi. I have a simple probability question:

Not counting the greens, what are the odds of getting 19 of the same color in a row in roulette?

I'm assuming the answer would be 0.5 to the 19th power.

I tried to do this in Excel, but it would not calculate it.

I'm thinking the answer is something like 1 in 500,000?

Please let me know if this is close.

Thanks! You guys are awesome!

#### Outlier

##### TS Contributor
My version of Excel gave me
1.90735E-06

I didn't know Google did exponentiation. . .

#### cmarkos111

##### New Member
Yes, I got "E-06" as well, but I was hoping to get the actual figure.

Thanks all! This is a great forum.

#### Dason

##### Ambassador to the humans
What do you mean by the 'actual figure'? Like the actual fraction? For that you just need to figure out 2^19 = 524288 so the fraction is 1/524288 exactly.

#### Outlier

##### TS Contributor
I'm an amateur but it's my sense that carrying three significant figures is probably accurate enough for most probability calcs.

#### Mean Joe

##### TS Contributor
Be careful that it could be 19 red in a row or 19 black in a row.

#### Dason

##### Ambassador to the humans
Ha. That's true, I got caught up in the actual calculation that I didn't really think about that stuff. Oh well. Plus it's not that much more difficult to find the probability when accounting for the greens so I don't really seem why we're ignoring them.