# Odds of getting 1 decent prize out of X chances, Y decent prizes, and Z total prizes.

#### The Magic WOmbat

##### New Member
I am invited to play a game where there are 10 good prizes, 300 losers prizes, and I have 5 tokens to spend playing, 1 per turn.

I know the odds on my first pull are:

10/300 = 3.33%

Second pull (provided I do not get a good prize on the first pull) are:

10/299 = 3.3445%

And so on...

Now, let's vary the mix:

What are the chances, before I do my first pull, that in using my ten tokens I will get at least one good prize, and how do I express said formula?

And, to make it really tricky, can this be done in Excel?

#### Dason

Re: Odds of getting 1 decent prize out of X chances, Y decent prizes, and Z total pri

Can you tell me the probability that you get 0 good prizes in 1 turn? In 2 turns?

#### The Magic WOmbat

##### New Member
Re: Odds of getting 1 decent prize out of X chances, Y decent prizes, and Z total pri

Well...

I have 10 chances. I have 10 good prizes. I have 290 bad prizes. My odds of getting a good prize in 1 turn is 3.333% Ergo, I am pretty sure my odds of NOT getting a good prize are 96.666%

As for my odds of getting at least 1 good prize in 2 attempts, that is pretty much my question.

Let me rephrase it...

I have a bag with 10 green marbles, and 290 red marbles. If I reach in and pull out 10 marbles at random, what are the odds I will pull out at least 1 green marble?