# Probability and odds?

• Jun 14th 2011, 09:26 AM
homeylova223
Probability and odds?
A box contains 1 green, 2 yellow, and 3 red marbles. Two marbles are drawn at random without replacement. What are the odds of each event occurring?

1. Drawing to different colours

I am kind of confused on how to start this problem. (Giggle)
• Jun 14th 2011, 09:43 AM
Plato
Re: Probability and odds?
Quote:

Originally Posted by homeylova223
A box contains 1 green, 2 yellow, and 3 red marbles. Two marbles are drawn at random without replacement. What are the odds of each event occurring?
1. Drawing to different colours?

I do not deal with odds.
But I can give the probabilities.
$\displaystyle \mathcal{P}(\{G,Y\})=2\left(\frac{1}{6}\cdot\frac{ 2}{5}\right)~,$ $\displaystyle \mathcal{P}(\{G,R\})=2\left(\frac{1}{6}\cdot\frac{ 3}{5}\right)~,~\&~,$ $\displaystyle \mathcal{P}(\{R,Y\})=2\left(\frac{3}{6}\cdot\frac{ 2}{5}\right)~$.

To have two different colours, it must be one of those three.

What is the answer?
• Jun 14th 2011, 10:39 AM
homeylova223
Re: Probability and odds?
As my answer I got 11/4 I added up all the success probabilities subtracted by one to get the failures and then I did probability of success/ probability of failure.