22 February 2011

Puzzle - Who is Knight and Who is Knave

This is a puzzle that i read in internet sometime last week and thought of sharing it here.

There is an island that has people who always speak truth (knight) or people who always lie (knaves). Unfortunately, you need find the way to the capital of the island. You are standing at the fork and there are two roads - left and right. There are three people, let us call them A, B and C, who are native of the island standing near the fork. You approach them, they tell you the following statements

Two of us are knaves, one of us is knight and the road in the left goes to the capital.

Will you be able to find which road goes to the capital - is it left or right? 

3 comments:

Srikanth said...

good one:

Herez the answer i believe may be correct:

When the person in subject ask: your Question says - "they tell", so I assume all the 3 are speaking at once:

That means all them tell equivocally : Two of us are knaves, one of us is knight and the road in the left goes to the capital.
If there is atleast one knave and one knight in the group of 3, the answer should not be equivocal.

So they are lying want they are. So all of them are knaves. So take the right of the road

Srikanth said...

good one:

Herez the answer i believe may be correct:

When the person in subject ask: your Question says - "they tell", so I assume all the 3 are speaking at once:

That means all them tell equivocally : Two of us are knaves, one of us is knight and the road in the left goes to the capital.
If there is atleast one knave and one knight in the group of 3, the answer should not be equivocal.

So they are lying want they are. So all of them are knaves. So take the right of the road

Bala Vijay said...

Answer is already given.
Anyways my solution.
If all three are knights, then Stmt A and B will be false.
If two are knights, then also Stmt A and B will be false.
If anyone is knight, then Stmt B is true, but Stmt A will be false because A is knaive. So, there are not 2 knaives. So, one knight is also impossible.
Hence, all are Knaives and the road in the right goes to capital.