Welcome to BrainDen.com - Brain Teasers Forum
|Welcome to BrainDen.com - Brain Teasers Forum. Like most online communities you must register to post in our community, but don't worry this is a simple free process. To be a part of BrainDen Forums you may create a new account or sign in if you already have an account.
As a member you could start new topics, reply to others, subscribe to topics/forums to get automatic updates, get your own profile and make new friends.
Of course, you can also enjoy our collection of amazing optical illusions and cool math games.
If you like our site, you may support us by simply clicking Google "+1" or Facebook "Like" buttons at the top.
If you have a website, we would appreciate a little link to BrainDen.
Thanks and enjoy the Den :-)
Posted 24 January 2008 - 03:29 PM
Each basket contains 4 balls, indistinguishable except for color.
There is a red, a white, a blue, and a black ball in each basket.
You are blindfolded and asked to remove one ball from each basket.
What are the chances you will pick exactly 2 red balls and 1 non-red ball?
- Bertrand Russell
Posted 24 January 2008 - 03:53 PM
= 1/4 * 1/4 * 3/4 * 3
Red Red Non-red The number of baskets where the non-red ball can be pulled
Posted 25 January 2008 - 02:30 AM
You are now asked to remove two balls from each basket (ie 6 balls total). Are you more likely to pick exactly [1 red ball and 5 non-red balls] or exactly [2 red balls and 4 non-red balls]? What are the chances?
extra credit - anyone can run the options out the long way (I did ) - but can you explain the math behind the result? I left my high-school math way behind, so don't have a clue what the formula would look like...
Posted 25 January 2008 - 08:09 AM
Are you more likely to pick exactly [1 red ball and 5 non-red balls] or exactly [2 red balls and 4 non-red balls]?
What are the chances?
- Bertrand Russell
0 user(s) are reading this topic
0 members, 0 guests, 0 anonymous users