probability

[deevicsm]

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]

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^st draw: \(\displaystyle \,\frac{14}{25}\)

The prob. of a non-yellow on the 2^nd 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]

Thanks, the more I thought about it the more it made since it was that way.