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#1 2007-03-26 19:02:14

soha
Real Member
Registered: 2006-07-07
Posts: 2,530

probability

please help me in the below problem .It is very confusing....dunno

From a pack of 52 cards ,red face cards are removed.After that a card is drawn at random from the pack.Find the probability that the card is drawn is:-

a)a queen
b)a red card
c)a spade card.

Last edited by soha (2007-03-26 19:02:36)


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#2 2007-03-26 20:39:22

mathsyperson
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Registered: 2005-06-22
Posts: 4,900

Re: probability

a) Removing reds doesn't change the probability of there being a queen. That means that the probability is 1/13, just like in a normal pack.

b) The probability of there being a red is clearly 0, because they all got removed.

c) With all the reds gone, all the cards in the pack are either clubs or spades, split equally. That means that the chance of there being a spade is 1/2.


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It wanted to be normal.

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#3 2007-03-26 21:08:02

JaneFairfax
Member
Registered: 2007-02-23
Posts: 6,868

Re: probability

Actually, soha said “red face cards”. I thought that meant red cards with faces on them – i.e. the jacks, kings and queens of hearts and diamonds? dunno

The probabilities would then be

(a) 2⁄46 = 1⁄23
(b) 20⁄46 = 10⁄23
(c) 13⁄46

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#4 2007-03-26 21:18:49

mathsyperson
Moderator
Registered: 2005-06-22
Posts: 4,900

Re: probability

Ah yes, you're probably right. Sorry!


Why did the vector cross the road?
It wanted to be normal.

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#5 2007-03-27 01:35:16

JaneFairfax
Member
Registered: 2007-02-23
Posts: 6,868

Re: probability

Well, I’m only guessing anyway. I’m guessing that “face” cards refer to jacks, queens and kings (though I’ve never heard them described that way).

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#6 2007-03-27 04:56:11

soha
Real Member
Registered: 2006-07-07
Posts: 2,530

Re: probability

yes .understood .may be you are right .
actually , this question came in my sister's board examinations.
so wanted to confirm it here whether ace should be taken as face card? .Should ace be taken as a face card.

well , thank you jane and mathsyperson for answering.


"Let us realize that: the privilege to work is a gift, the power to work is a blessing, the love of work is success!" smile smile
- David O. McKay

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#7 2007-03-27 05:16:45

pi man
Member
Registered: 2006-07-06
Posts: 251

Re: probability

In America,  the Jacks, Queens and Kings are called face cards for the obvious reason that those are the cards with people's faces on them.   Aces are not face cards.

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#8 2007-03-27 05:21:30

soha
Real Member
Registered: 2006-07-07
Posts: 2,530

Re: probability

thanks for answering ,piman .


"Let us realize that: the privilege to work is a gift, the power to work is a blessing, the love of work is success!" smile smile
- David O. McKay

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