Math Is Fun Forum

juantheron

Member

Registered: 2011-10-19

Posts: 312

probability

There are 6 couples (12 people). 4 people are selected at random. What is the probability that exactly one couple will be selected

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: probability

Hi;

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

anonimnystefy

Real Member

From: Harlan's World

Registered: 2011-05-23

Posts: 16,049

Re: probability

P(exactly 1 pair selected)=1- ( P(no pairs selected) + P(2 pairs selected) )

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“Here lies the reader who will never open this book. He is forever dead.
“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

juantheron

Member

Registered: 2011-10-19

Posts: 312

Re: probability

Thanks Bobbym and anonimnystly

Yes Bobbym you are Right

but would you like to explain it to me

Thanks

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: probability

Hi;

You can choose 2 pairs in

You can choose 4 cards in

So the probability of 2 pairs is 1 / 33

You can have no pairs in

ways.

So the probability of 0 pairs is 16 / 33

The complement is the probability of 1 pair.

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.