Monday

September 15, 2014

September 15, 2014

Posted by **Katia** on Monday, December 13, 2010 at 7:34pm.

From the box containing 5 red balls, 7 blue balls, 10 black balls. you select 4 balls

what is the probabilty that EXACTLY 2 balls are black.

so i know how to start it

c(10,2)c(2,1)

----------

c(22,40

but how do you solve that ?

- Math -
**Katia**, Monday, December 13, 2010 at 7:35pmi meant c(10,2)c(2,1) divided by c(22,4)

- Math -
**Reiny**, Monday, December 13, 2010 at 9:48pmso we want 2 from the black, then 2 more from the rest

prob of that = C(10,2) C(12,2) / C(22,4)

**Answer this Question**

**Related Questions**

Math - my problem is: From the box containing 5 red balls, 7 blue balls, 10 ...

Math - A box containing 20 yellow balls, 9 red balls and 6 blue balls. If the ...

maths-probabilty - A box contains 5 red balls and 6 black balls. in how many ...

maths-probabilty(urgently needed) - A box contains 5 red balls and 6 black balls...

Math - Four balls are simultaneously picked at random from a jar containing 2 ...

math - A box contains 8 blue balls and 2 red balls. Three balls are selected ...

math - we have box,in box 3 white balls,4 red balls,4 black balls..how i choose ...

Statistics - I have two boxes with balls; box #1 and box #2. Box #1 has 3 red ...

Probability again - A box contains 6 red balls, 4 blue balls, and 2 green balls...

Basic Mathematics - A bag contains 2 red balls, 3 blue balls and 5 green balls. ...