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#1 2012-11-23 12:25:19

infinitebrain
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Registered: 2008-07-01
Posts: 153

Probability Question

Six boys and twelve girls are in a senior class.Half the boys and 25% of the girls wear glasses.What is the chosen probability that a student chosen randomly is a boy,wears glasses,or both? I know the answer is 50%, but could someone could explain to me clearly how you get that answer? Thanks!


The best thing about life is you don't know what to expect

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#2 2012-11-23 14:19:58

Agnishom
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From: Riemann Sphere
Registered: 2011-01-29
Posts: 21,941
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Re: Probability Question

Probability that the chosen one is a boy =


Probability that the chosen one wears glasses =

Probability that the chosen one is both a boy and wears glasses = (Probability of being a boy) * (Probability of a boy to wear glasses) =

Last edited by Agnishom (2012-11-23 14:22:47)


'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
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#3 2012-11-23 14:35:03

infinitebrain
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Registered: 2008-07-01
Posts: 153

Re: Probability Question

Thank you Agnishom! big_smile
Sorry, I went back to look at the documents and it said A is correct, which is 16 2/3%! smile


The best thing about life is you don't know what to expect

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#4 2012-11-23 14:41:15

Agnishom
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From: Riemann Sphere
Registered: 2011-01-29
Posts: 21,941
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Re: Probability Question

You are Welcome, @infinitebrain


'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'
'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'
'But our love is like the wind. I can't see it but I can feel it.' -A Walk to remember

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