# If only one of the statements is true, then who is the murderer?

802 views

If only one of the statements is true, then who is the murderer?
X: Y is the murderer
Y: Z id the murderer
Z: neither X nor Y is the murderer

posted Feb 11, 2016

+1 vote

Y is the murderer.

If the murderer is Z then - both Y and Z statements are correct.
If the murderer is X then all statements are wrong.

Therefore answer can only be Y

Y is the Murderer.

What is the logic?
If we assume Y speaks the truth, then Z's statement also becomes true.
Similarly, If we assume Z speaks the truth, then Y's statement also becomes true.
But only 1 Statement out of 3 is true.
So statement given by X is true - Y is the murderer.

Y is the murderer

assume X is saying the truth i.e Y is the murderer
Y says Z is murderer which is a false statement
Z says X&Y aren't the murderers which is also false.

assume Y is saying the truth i.e Z is the murderer
then X & Z are also telling the truth.

assume Z is saying the truth i.e X & Y aren't murderers i.e Z is the murderer
then X & Y are also telling the truth

Similar Puzzles

Billy "The Knife," the infamous tough guy, was found murdered one night in an alleyway behind the nightclub he used to frequently visit. The police brought in three suspects on the next morning. One of the officers interrogated the three men and noted down the following statements.

Alex:
1. I did not kill Billy.
2. Jimmy is not my friend.
3. I knew Billy.

Jimmy:
1. I did not kill Billy.
2. Alex and Dexter are friends of mine.
3. Alex did not kill Billy.

Dexter:
1. I did not kill Billy.
2. Alex lied when he said that Jimmy was not his friend.
3. I do not know who killed Billy.

Only one of the three is guilty, and only one of each man statements is false. Who killed Billy the Knife ?

Two of the following statements are true and the other one is false:

1. This statement is true.
2. The first statement is false.
3. The second statement is true.

Which statement is false?

The police rounded up Jim, Bud and Sam yesterday,
because one of them was suspected of having robbed a bank.
The three suspects made the following statements under intensive questioning:
Jim: I'm innocent.
Bud: I'm innocent.
Sam: Bud is guilty.
If only one of these statements is true,
who robbed the bank?