Tuesday

July 22, 2014

July 22, 2014

Posted by **Stuck** on Monday, May 3, 2010 at 8:45pm.

(Answer: 1/28)

So I thought about doing 4 cases and then adding them up (don't pick red ball in A, don't pick red ball in B...pick red ball in A, pick red ball in B...etc...).

I did this:

(3/8)(3/7)(6/10)(6/9) +

(3/8)(2/7)(6/10)(5/9) +

.....

But it doesn't work. What am I doing wrong?

- Math -
**Reiny**, Monday, May 3, 2010 at 9:46pmSince you pick 2 from each vase, and you want 4 reds, there is only one way, that is, you pick 2 from A and 2 from B.

which is C(3,2)/(C(8,2) * C(6,2)/C(10,2)

= 3/28 * 15/45 = 1/28

- Math -
**Stuck**, Monday, May 3, 2010 at 10:17pmOh yeah! Thank you!

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