Test Jump to content
The British Coin Forum - Predecimal.com

Recommended Posts

Posted (edited)

I think it's harder than most things I was given to solve at school, certainly before the age of 16. But it's not really maths, just logic/deduction.

Edited by Paulus
Posted

Try this one. A logic professor has three students in his class and he has 8 stamps on his desk. Four stamps are green and four are red. The professor then sticks two stamps onto the foreheads of each student and leaves the two remaining ones face down on his desk. The result is that any one student can see what's on the foreheads of the other two students, but not what is on his own forehead and not what is on the table. There are no mirrors or reflecting surfaces in the room.

He then says to the first student 'Do you know what stamps are on your forehead, and the first student says 'no'. He then asks the second student the same question and again the student says 'no.' The professor then asks the third student and he again says 'no.' He then goes back to the first student and asks if he knows what stamps the student has on his forehead and again the student thinks for a minute and says ,'no.' Finally, he turns to the second student for the second time and asks the same question. This time the students says yes', he knows and the stamps are........

For numismatic interest substitute coins for stamps, although how he gets them to stick is a moot point. Don't try it at home with cartwheel tuppences.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...
Test