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Ana had a birthday today and she have a whole cake... Here is the problem.. The cake have a  5 glass shard ... There are 10 people who is hungry (INCLUDING YOU) and the cake is equivalent into 10 pieces... There are 1/2 chance of you of eating the glass shard... (50%). Two of the hungry people knows where the 2 glass shard is... But there are possibilities... 

1.) one of them are lying and the other one is not

2.) both of them might lie

3.) both of them must be right

How can you OVERCOME the glass shard?




riddle by Ted-Ed

 Aug 29, 2018
edited by Guest  Aug 29, 2018
edited by Guest  Aug 29, 2018

I can be one of the 2 hungry people who knows where the glass is so I am not going to eat one of those. 


I guess this is not the answer that you are hoping for :)




How about.

Let the 2 who know each chose a good peice, then allow them to eat the peice they chose. They are hungry so it they really have chosen a good peice they will eat it and they were telling the truth. If they don't eat it it is because there is glass in that slice and they are lying.


If they both eat it then you can just ask them to sort the good from the bad, they are both telling the truth so they will agree on the out come and the 3 remaining good pieces will be identified.

If neither eat it then they are both liars. You can get them to sort out the 5 good and 5 bad ones 


If neither eat it then you can again ask them to sort the good from the bad, they are both lying so they will agree on the out come.  The 5 that they say are good are the bad ones

If one eats the cake and one doesn't then it is obvious that the eater is telling the truth and the onther is lying.

Get the truth teller to point out the other 4 good ones. 

 Sep 1, 2018
edited by Melody  Sep 1, 2018

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