Calculating Probability of Extracting 5 Pairs of Different Colored Balls

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SUMMARY

The discussion focuses on calculating the probability of extracting pairs of differently colored balls from a box containing 5 white and 5 black balls. The random variable X represents the number of extractions of balls with the same color, ranging from 0 (all pairs are different colors) to 5 (all pairs are the same color). The probabilities for X are given as P(X=0) = 8/63, P(X=2) = 40/63, and P(X=4) = 15/63. The challenge lies in determining the total number of possible extraction events and the specific events of interest where all pairs consist of different colors.

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etf
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Hi!
Here is my task:
There are 5 white and 5 black balls in box. Two balls at the time are extracted from box. Let random variable X be "number of extractions of balls with same colour. Find probability of random variable.

x can go from 0 (5 times we extract two by two balls and they are with different colour) to 5 (5 times we extract two by two balls and they are with same colour). I started with P(x=0) and I stucked there. How to calculate number of all possible events when extracting two by two balls at the time and number of all possible events of interest (we extract 5 pairs of balls and they are with different colours)?
Few events of interest woul be for example:
black ball white ball, black ball white ball, black ball white ball, black ball white ball,black ball white ball or
white ball black ball, white ball black ball, white ball black ball, white ball black ball, white ball black ball or
white ball black ball, black ball white ball, black ball white ball, black ball white ball, white ball black ball
etc.
 
Last edited:
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Result is:
$$X: \begin{pmatrix}
0 & 2 & 4 \\
8/63 & 40/63 &15/63
\end{pmatrix} $$
 
etf said:
Hi!
Here is my task:
There are 5 white and 5 black balls in box. Two balls at the time are extracted from box. Let random variable X be "number of extractions of balls with same colour. Find probability of random variable.

x can go from 0 (5 times we extract two by two balls and they are with different colour) to 5 (5 times we extract two by two balls and they are with same colour). I started with P(x=0) and I stucked there. How to calculate number of all possible events when extracting two by two balls at the time and number of all possible events of interest (we extract 5 pairs of balls and they are with different colours)?
Few events of interest woul be for example:
black ball white ball, black ball white ball, black ball white ball, black ball white ball,black ball white ball or
white ball black ball, white ball black ball, white ball black ball, white ball black ball, white ball black ball or
white ball black ball, black ball white ball, black ball white ball, black ball white ball, white ball black ball
etc.

Show some work. For example, how would you compute the probability that all pairs have different colours?
 

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