Your verification ID is: guDlT7MCuIOFFHSbB3jPFN5QLaQ Big Computing: A Fun Problem to play with....

Saturday, April 9, 2011

A Fun Problem to play with....

I am always on the lookout for interesting brain teasers, and this is a fun one. It comes from a blog by Phil Birnbaum which I found a few days ago and I just love. His Sabermetrics stuff is awesome!

A king decides that his country has too many men and not enough women. So he issues a decree: once a couple has a boy, they're not allowed to have any more babies.

The king reasons as follows: no family will have more than one boy. But some families will have two girls, or three girls, or even six girls before they have a boy. So there will wind up being a lot more girls than boys.

Is the king's reasoning correct?
The answer: the king's reasoning is not correct. There will still be approaching 50 percent boys, and 50 percent girls. There are many ways to figure this out. 

I believe this assumes that the chances of having a boy or girl are equally likely. and independent.