This was astronaut Jose Perez’s fourth visit to Mars
and he had learned to speak Martian. He wanted to
find his Martian friend Doman, but in order to locate
him he had to know what group Doman belonged to.
The three groups in the area were: Uti, Yomi, and
The Uti always told the truth.
The Yomi always lied.
The Grundi sometimes told the truth but sometimes
Perez needed information. Three Martians, Aken, Bal
and Cwos, each of whom belonged to a different group,
agreed to help him. He asked each one of them two
questions: What group do you belong to? What group
does Doman belong to?
1. Aken said:
I am not a Uti.
Doman is a Yomi.
2. Bal said:
I am not a Yomi.
Doman is a Grundi.
3. Cwos said:
I am not a Grundi.
Doman is a Uti.
What group does Doman belong to?