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  #1  
Old 06-21-2007, 03:21 PM
evans075 evans075 is offline
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Default Math question.

Two questions that a teacher of mine asked in class but didn't have time to explain the answers to. I've been racking my brain on how to work these two questions. So could someone explain how you would go about doing this!!!

How many different 8 card hands are there that contain exactly 2 suites with 4 cards from each suite?

How many different 8 card hands are there that contain only face cards?
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  #2  
Old 06-21-2007, 04:29 PM
theflyingcow theflyingcow is offline
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Default Re: Math question.

Quick question that pertains more to the 2nd one, do suits matter, like a hand containing the A[img]/images/graemlins/club.gif[/img] would be different from an identical one containing the A[img]/images/graemlins/diamond.gif[/img]? E.g. AQQQ.
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  #3  
Old 06-21-2007, 04:37 PM
evans075 evans075 is offline
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Default Re: Math question.

Yes one containing A [img]/images/graemlins/club.gif[/img] would be different from one containing A [img]/images/graemlins/diamond.gif[/img] in AQQQ
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  #4  
Old 06-21-2007, 05:22 PM
jesse8888 jesse8888 is offline
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Default Re: Math question.

C(X Y) is going to be used to mean X choose Y. I think these are right, but would appreciate double checking.

Second question: C(12 8) or (12!)/((8!)*(4!)) = 495
There are 12 face cards, you must choose 8.

First question: C(4 2) * C(13 4) = 4290
There are 4 suits, you must choose 2, and there are 13 cards of which you must choose 4.
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  #5  
Old 06-21-2007, 06:32 PM
jogsxyz jogsxyz is offline
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Default Re: Math question.

1. 13C2 * 13C2 * 13C2 * 13C2
In each of the 4 suits there are 13 cards. You choose 2 from each of the suits.
52C8
You choose 8 from the 52 card deck.
13C2 = 13*12/(2*1) = 78
52C8 = 52*51*...45/8! = whatever
78*78*78*78
guess you don't need the denominator.
you calculate it.
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  #6  
Old 06-21-2007, 07:16 PM
alThor alThor is offline
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Default Re: Math question.

[ QUOTE ]
C(X Y) is going to be used to mean X choose Y. I think these are right, but would appreciate double checking.

Second question: C(12 8) or (12!)/((8!)*(4!)) = 495
There are 12 face cards, you must choose 8.

First question: C(4 2) * C(13 4) = 4290
There are 4 suits, you must choose 2, and there are 13 cards of which you must choose 4.

[/ QUOTE ]

Did you mean:
First question: C(4 2) * C(13 4) * C(13 4)
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  #7  
Old 06-23-2007, 01:26 AM
filsteal filsteal is offline
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Default Re: Math question.

[ QUOTE ]
[ QUOTE ]
C(X Y) is going to be used to mean X choose Y. I think these are right, but would appreciate double checking.

Second question: C(12 8) or (12!)/((8!)*(4!)) = 495
There are 12 face cards, you must choose 8.

First question: C(4 2) * C(13 4) = 4290
There are 4 suits, you must choose 2, and there are 13 cards of which you must choose 4.

[/ QUOTE ]

Did you mean:
First question: C(4 2) * C(13 4) * C(13 4)

[/ QUOTE ]

I hope he did, because your answer is correct. You need a C(13 4) for EACH suit.
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  #8  
Old 06-24-2007, 01:15 AM
jogsxyz jogsxyz is offline
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Default Re: Math question.

[ QUOTE ]
[

Did you mean:
First question: C(4 2) * C(13 4) * C(13 4)

[/ QUOTE ]

Misread the question. That's the answer to question 1.
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