# Dependent Events

• December 17th 2009, 07:09 PM
kilgoretrout
Dependent Events
Am I doing this question right so far? I need your feedback.

"A bag contains 30 poker chips of different colors. They consist of the following:

Blue Chips: 11
Green Chips: 7
Red Chips: 2
White: 10

If 4 poker chips are drawn from the bag without replacement, what is the probability of drawing one poker chip of each color?"

So far, I have:

P (BGRW) = 11/30 x 7/29 x 2/28 x 10/27

(Speechless)

Is it right thus far or am I forgetting something?

Thankyou!
• December 17th 2009, 08:38 PM
matheagle
This is a hypergeometric and its better to use the choose formula.

${ {11\choose 1}{7\choose 1}{2\choose 1}{10\choose 1}\over {30\choose 4}}$

You need an extra 4!=24 if you do it your way.
My way takes out the order.
• December 18th 2009, 06:14 PM
kilgoretrout
Ah, thanks matheagle.