lucky door math problem

Bot Solutions

Regular Member

Aug 19, 2014

264

458

• Jun 10, 2018

• #1

There are 3 doors; 2 empty, 1 has money behind it.

You want to choose the door which has the money.

You pick a door, then I show you an other door which does not have the money behind it.

Do you change your pick? Why?

Vote before you check the solution!
Solution:
https://jsfiddle.net/12Ldrypc/
(change first line to true or false)

 

D

Deleted member 719276

Guest

• Jun 10, 2018

• #2

Sir me bash my head one time in 1 door and now need to change it

 

SPQR

Elite Member

May 15, 2013

1,874

1,076

• Jun 10, 2018

• #3

Change the pick. The original odds are 1/3, however once the door is revealed to have nothing behind it, you can use that information to your advantage. When you change your pick, you're odds are now 1/2.

 

Bot Solutions

Regular Member

Aug 19, 2014

264

458

• Jun 10, 2018
• Thread Starter Thread Starter

• #4

SPQR said:

Change the pick. The original odds are 1/3, however once the door is revealed to have nothing behind it, you can use that information to your advantage. When you change your pick, you're odds are now 1/2.

Click to expand...

It is actually 2/3 if you change your pick.
If you pick wrong for the first time and then you change your pick then you win for sure.
You have 2/3 chance to pick the wrong door.
jsfiddle also proves it

 

riz_a

Junior Member

Mar 30, 2017

115

112

• Jun 10, 2018

• #5

 

Dominor001

Power Member

Dec 22, 2015

518

298

• Jun 10, 2018

• #6

That's really mind-blowing lol