RE: Intelligence test
September 8, 2015 at 10:59 pm
(This post was last modified: September 8, 2015 at 11:01 pm by Alex K.)
Losty, ok.
If we allow for a sometimes, the main part of the riddle becomes (in my first reading)
1. Exactly one of us sometimes lies
2. Exactly one of us sometimes tells the truth
The riddle itself has the extra info (which renders it a bit stupid) that the first guy is right in this instance. This means that one of them does not sometimes lie, i.e. that one of them *always* tells the truth.
I) Let this be the first person.
Assume the second one were lying in this instance, we invert his statement and the truth would be that it is not exactly one of them who sometimes tells the truth. One of the remaining possibilities is that both of them sometimes tell the truth, *but not in this instance*.
It is therefore a consistent hypothesis even with the additional stupid comment that *in this instance*, the first person tells the truth and the second person lies.
If we allow for a sometimes, the main part of the riddle becomes (in my first reading)
1. Exactly one of us sometimes lies
2. Exactly one of us sometimes tells the truth
The riddle itself has the extra info (which renders it a bit stupid) that the first guy is right in this instance. This means that one of them does not sometimes lie, i.e. that one of them *always* tells the truth.
I) Let this be the first person.
Assume the second one were lying in this instance, we invert his statement and the truth would be that it is not exactly one of them who sometimes tells the truth. One of the remaining possibilities is that both of them sometimes tell the truth, *but not in this instance*.
It is therefore a consistent hypothesis even with the additional stupid comment that *in this instance*, the first person tells the truth and the second person lies.
The fool hath said in his heart, There is a God. They are corrupt, they have done abominable works, there is none that doeth good.
Psalm 14, KJV revised edition
