Verbal Reasoning - Mental Ability Questions

P is the brother of Q. Q is the brother of R. P is the son of S. Based these three statements, much of the following statements cannot be definitely true?

In the following question, select the related number from the given alternatives. 850 : 863 : : 430 : ?

Select the related word/letters/numbers from the given alternatives:
3 : 243 :: 5 : ?

What will come in place of the question mark (?) in the following number series?14, 18, 9, 25, 0, ?

In the following question, select the related number from the given alternatives.
48 : 63 : : 80 : ?

'E' is related to 'BH' in the same way as 'N' is related to?

Select the Missing number?

A series is given, with one term missing. Choose the correct alternative from the given ones that will complete the series.

OXXXXX, XXXXO, OXXX, XXO, OX, ?