You are shown three boxes, and told that one of them contains a prize. You are then asked to pick one box, and if that box is the one with the prize, you will win it. After picking a box, you are shown that one of the other two boxes is empty, and offered a chance to change your selection.

Should you do this? Would changing your choice to the other remaining box affect your odds of winning? Why or why not?

(In reply to NO! 50/50! All possibilites shown! by jduval)

I guess we can not paste charts from Excel. I will redraw my chart here.  You can go back to the gibberish and count the Ys and Ns, but this will be easier.

Switch Yes      Switch No

p P S W          p P S W

1 1 2 N           1 1 2 Y

1 1 3 N           1 1 3 Y

1 2 3 Y           1 2 3 N

1 3 2 Y           1 3 2 N

Again p= box picked, P = box with prize, S = box shown, W = prize won?

50/50

 

 

 

Posted by john on 2005-03-01 17:24:54