A bag contains five white balls and five black balls. Your goal is to draw two black balls.

You draw two balls at random. Once you have drawn two balls, you put back any white balls, and redraw so that you again have two drawn balls. What is the probability that you now have two black balls? (Include the probability that you chose two black balls on the first draw.)

ABJ11 Oct 23, 2019

#1**+4 **

**Please do not post solutions to this problem!**

This is a homework problem, and the original poster is simply trying to cheat.

wonderman Oct 23, 2019

#3**+1 **

I know that unfortunately, there are some users that might want to cheat, but we can't just assume that every person who asks a specific question is a cheater...

maybe OP is actually trying to learn the material....

:')

Nirvana
Oct 24, 2019

#5**+4 **

This problem is taken from an online class, where there are several rules, covering things such as plagiarism and giving credit for collaboration. Academic integrity is an important part of these rules.

In particular, external internet websites should not be used. So posting the problem on this website, regardless of the intention, is already an infringement.

wonderman
Oct 24, 2019

#7**+2 **

ah, well that's another thing...

academic dishonesty is NEVER okay :0

but OP if you are actually willing to learn how to do this, maybe make a problem similar to it? idk...so it doesn't look like you're like trying to cheat or anything. And, maybe you weren't intending to do that, but yeah...

Nirvana
Oct 26, 2019

#4**+1 **

I have not worked this question out but I would most likely look at the different probabilities and then add them together

P(BB)

+ P(WW throw back and get BB) on second try)

+ P(BW throw back the white one and get a black next time)

+ P(WB throw back the white one and get a black next time)

Melody Oct 24, 2019