Probability Prediction

[DummyAllien]

I have encountered a probability problem and need help. If I have equal amounts of blue and red color ball in a bag and I pick two balls every time randomly from the bag, the probability to get the 2 red ball/1 red ball, 1 blue ball/2 blue balls is 25%/50%/25%. Now I have 30% of red and 70% of blue ball in the bag at the beginning and I still pick up two balls every time, what is the probably ratio to get 2 red/1 red, 1 blue/2 blue? If anyone can provide the answer and the equation to predict will be really appreciate. Thanks.

 

[stapel]

If I have equal amounts of blue and red color ball in a bag and I pick two balls every time randomly from the bag, the probability to get the 2 red ball/1 red ball, 1 blue ball/2 blue balls is 25%/50%/25%.

Now I have 30% of red and 70% of blue ball in the bag at the beginning and I still pick up two balls every time, what is the probably ratio to get 2 red/1 red, 1 blue/2 blue?

What was your reasoning for figuring out the answer to the first question? What did you get when you tried applying that same reasoning to the second question?

Please be complete. Thank you!

 

[HallsofIvy]

If you don't like to work with percentages, imagine the bag containing 10000 balls, 3000 red and 7000 blue. What is the probability the first ball will be red? What is the probability the second will be red.

That would probably give a better answer than the "30%" and "70%" you are using because, if you actually have some number of balls in a bag then as soon as a single ball is drawn, the number of balls in the bag, and so the percentages, will change.

 

[Ishuda]

I have encountered a probability problem and need help. If I have equal amounts of blue and red color ball in a bag and I pick two balls every time randomly from the bag, the probability to get the 2 red ball/1 red ball, 1 blue ball/2 blue balls is 25%/50%/25%. Now I have 30% of red and 70% of blue ball in the bag at the beginning and I still pick up two balls every time, what is the probably ratio to get 2 red/1 red, 1 blue/2 blue? If anyone can provide the answer and the equation to predict will be really appreciate. Thanks.

Please note that you are talking about replacement of the balls after drawing. If you do not replace the balls the probability changes.