probability

deevicsm

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Joined
Apr 2, 2006
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7
Here is the homework question - Jar containing 3red 7 green 4 blue 11 yellow marbles 25 total.
You randomly draw 2 marbles what is the probability of neither being yellow? I said .56% or 14/25 (or should it be 14/25 X 13/24 = )
 

soroban

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Jan 28, 2005
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5,588
Hello, deevicsm!

Jar containing 3 red, 7 green, 4 blue, 11 yellow marbles ... 25 total.
You randomly draw 2 marbles.
What is the probability of neither being yellow?
Your first answer is the probability of getting a non-yellow in one draw.


Your second answer is correct.

The prob. of a non-yellow on the 1<sup>st</sup> draw: \(\displaystyle \,\frac{14}{25}\)

The prob. of a non-yellow on the 2<sup>nd</sup> draw: \(\displaystyle \,\frac{13}{24}\)


Therefore: \(\displaystyle \,P(\text{two non-yellows})\;=\;\frac{14}{25}\,\time\frac{13}{24}\;=\;\frac{91}{300}\;\approx\;30\%\)
 

deevicsm

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Apr 2, 2006
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7
Thanks, the more I thought about it the more it made since it was that way.
 
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