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A bag contains 6 red balls and 9 black balls. two draws are made. find the probability that the first draw will give 4 red and second draw will give 3 black balls. when 1) balls are replaced after the first draw 2) balls are not replaced

I tried this

By Replacing balls

1) 15C4

2) 15C3

By non Replacement

1) 15C4

2) 11C3

Is this correct?

Or

By Replacing balls

1) 4/15

2) 3/15 = 1/5

By non Replacement

1) 4/15

2) 3/11

Is this correct?

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Since you are new, I want to give you some advice about the site: To get the best possible answers, you should explain what your thoughts on the problem are so far. That way, people won't tell you things you already know, and they can write answers at an appropriate level; also, people are much more willing to help you if you show that you've tried the problem yourself. Many would consider your post rude because it is a command ("Find..."), not a request for help, so please consider rewriting it. –  Zev Chonoles Jan 5 '13 at 5:26
1  
How many balls are drawn on the first draw? Second draw? Is it $4$ and $3$ respectively? –  André Nicolas Jan 5 '13 at 5:35
    
@ZevChonoles thanks for your advice sorry for this "find" i just made my question as title –  nishanthan Jan 5 '13 at 5:47
    
@AndréNicolas i'm also confused on this so that i posted it here –  nishanthan Jan 5 '13 at 5:48
    
And there are a couple of interpretations of "with replacement." We could draw a total of say $4$ on the first draw, one at a time, replacing each time, or remove them all at once, replacing only when it is time for the second draw. If this is homework, I assume the question must be more explicit than what you have written. –  André Nicolas Jan 5 '13 at 5:52
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