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# There are 8 TV sets, 6 are color and 2 are black and white.

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Senior Manager
Joined: 08 Aug 2005
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There are 8 TV sets, 6 are color and 2 are black and white. [#permalink]

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26 Apr 2006, 03:38
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

There are 8 TV sets, 6 are color and 2 are black and white. If 2 sets are selected at random, what is the probability that atleast one of them is color.

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Intern
Joined: 02 Mar 2006
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26 Apr 2006, 03:41
(6c1 * 2c1) + 6c2 = 27

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Senior Manager
Joined: 08 Aug 2005
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26 Apr 2006, 03:50
Please explain all the answers you are posting. Stating a one line solution is not much of help!

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Director
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26 Apr 2006, 03:55
hallo
The prob that there is AT LEAST one color TV is equal to 1-prob there is none. Then total possibilities-2C8=28 , when only BW are selected-2C2=1 and the prob required is 1-1/28=27/28
hope it is of use

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Intern
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26 Apr 2006, 03:59
selecting atleast a color set......

picking one color set out of 6 and one black setout of 2 = 6c1*2c1

picking two color sets from 6 = 6c2

(as arrangement is not a problem we will use combination here)

therefore combining two we get = (6c1*2c1) + (6c2)

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GMAT Club Legend
Joined: 07 Jul 2004
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26 Apr 2006, 04:02
The fastest way is to find the probability that none is a color set and subtract that from 1.

P(none is color) = 2/8 * 1/7 = 2/56

P(at least one is color) = 1 - 2/56 = 54/56 = 27/28

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VP
Joined: 06 Jun 2004
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28 Apr 2006, 23:14
ywilfred wrote:
The fastest way is to find the probability that none is a color set and subtract that from 1.

P(none is color) = 2/8 * 1/7 = 2/56

P(at least one is color) = 1 - 2/56 = 54/56 = 27/28

Agree with ywilfred's working
_________________

Don't be afraid to take a flying leap of faith.. If you risk nothing, than you gain nothing...

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28 Apr 2006, 23:14
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# There are 8 TV sets, 6 are color and 2 are black and white.

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