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In a village there are only two types of people. Type F are those who always lie and Type T always tell the truth.

X says “according to Y, I always lie”.

Assume both X and Y belong to above mentioned village

Which of the following is not possible?

I) X and Y both are Type F

II) X and Y both are Type T

III) X is type F and Y is Type T

IV) X is type T and Y is Type F
in Mathematical Logic by
edited by | 175 views
ii and iii not possible
Yup I felt the same too, but key is just ii. I couldn't get why.
If Y tells truth and X tells lie, then If Y says X lies then X will not tell this truth to us that  what y says about him.

iii is not possible.

If both tell truth then Y can't call X lier. so ii is not possible.

where did you see answer key?
At the end of the test :P

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