In a certain code, 'MTOF' is written as 'NUPG' and 'EBUF' is written as 'FCVG'. How will be 'AITF' be written in that code?

In a certain code language 'ne ri so' means 'good rain day', 'si ne po' means 'day is wonderful' and 'ri jo' means 'good bye'. Which of the following means 'rainy' in that code? 

The son of an old man is the uncle of my son. Tell me, what is the relation of the only son of the only daughter of my mother to that old man?

Who will be A's mother's sister's sister's son's sister?

C is the mother of A and B. If D is the husband of B, then who is C to D?

X and Y are brothers. R is the father of Y. S is brother of T and maternal uncle of X. How is T related to R?

Pointing to a woman, Simon said, "She is the daughter of the only sister of my father." How is the woman related to Simon?

Select the related word/letters/number from the given alternatives.

Optimist : Happy : : Pessimist : ?