## Wednesday, February 22, 2012

### Three Doors, 1 Prize Puzzle , One of Toughest Puzzle on Probabality

You are on a gameshow and the host shows you three doors. Behind one door is a suitcase with \$1 million in it, and behind the other two doors are sacks of coal. The host tells you to choose a door, and that the prize behind that door will be yours to keep.
You point to one of the three doors. The host says, "Before we open the door you pointed to, I am going to open one of the other doors." He points to one of the other doors, and it swings open, revealing a sack of coal behind it.
"Now I will give you a choice," the host tells you. "You can either stick with the door you originally chose, or you can choose to switch to the other unopened door."
Should you switch doors, stick with your original choice, or does it not matter?

Sushant Singla said...

You should change ur selection bcoz earlier u had 2/3 provability of selecting the wrong door.now it became 1/2.so its better to change it.

You can see it in this way
Suppose you have 1,2and 3 doors.
There is money in door 1.you can select either one.
if u select 1 then host will open 2 or 3.if you change yoy will LOOSE.

if you will select 2 then host will open 3.if you change you will WIN.

if you will select 3 then host will open 2.if u change you will WIN.

In 2 cases you WIN by changing and in one case you loose by changing .its better to change.

Nagaraju said...

You can find better explanation here http://en.wikipedia.org/wiki/Monty_hall_problem

Praveen said...

Wikipedia has good explantion for solution to this puzzle. Find it here:
http://en.wikipedia.org/wiki/Monty_hall_problem