Verbal Reasoning - Mental Ability Questions

In the following question, from the given alternative words, select the word which cannot be formed using the letters of the given word.
Biological

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, ?

Select the related word/letters/number from the given alternatives.
GT : IV : : KX : ?

How many triangles are there in the given figure?

In the following question, select the related letters from the given alternatives.
JPC : GMZ : : PUV : ?

If A=1, CAT=60, then MAN=?

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

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