# Data Management - Probability Distributions question 2

• Jan 4th 2009, 08:40 PM
Faisal2007
Data Management - Probability Distributions question 2
The door prize at a dance includes 4 - $10 gift certs, 5$20 certs and 3 $50 certs. 5 prizes are drawn at random, what is the prob. that none of the prizes is a$10 gift cert ?

I am trying my best and will edit the post with whatever i got =)
• Jan 4th 2009, 08:56 PM
mr fantastic
Quote:

Originally Posted by Faisal2007
The door prize at a dance includes 4 - $10 gift certs, 5$20 certs and 3 $50 certs. 5 prizes are drawn at random, what is the prob. that none of the prizes is a$10 gift cert ?

I am trying my best and will edit the post with whatever i got =)

There are a number of ways of solving this. Drawing a tree diagram is a good way.

Another way leads to this answer: $\displaystyle \frac{^8C_5 \cdot ^4C_0}{^{12}C_5}$. Do you see where it comes from?
• Jan 4th 2009, 09:02 PM
Faisal2007
Quote:

Originally Posted by mr fantastic
There are a number of ways of solving this. Drawing a tree diagram is a good way.

Another way leads to this answer: $\displaystyle \frac{^8C_5 \cdot ^4C_0}{^{12}C_5}$. Do you see where it comes from?

Oh yes..>I see it now !!!

Thanks alot for the jump start....

Its the formula to find the prob. in a hyper geometric distribution.

I couldnt figure out a way to use that formula with that question..

Guess i am approaching questions the wrong way...

Thanks alot again sir.