Thread: drawing marbles from a bag

if there are 20 white marbles and 32 black marbles in a bag
what is the probability of drawing 20 marbles where 10 are white and 10 are black ?
is there a formula ?

Originally Posted by addison

if there are 20 white marbles and 32 black marbles in a bag
what is the probability of drawing 20 marbles where 10 are white and 10 are black ?
is there a formula ?

Yes. Read this: Hypergeometric distribution - Wikipedia, the free encyclopedia.

In your case: N = 52, n = 20, m = 20, k = 10.

Hello, addison!

There are 20 white marbles and 32 black marbles in a bag.
What is the probability of drawing 20 marbles where 10 are white and 10 are black?

There are: . possible outcomes.

To draw 10 white marbles, there are: . ways.

To draw 10 black marbles, there are: . ways.

. . Hence, there are:\ . ways to get 10 white and 10 black marbles.


Therefore: .