Verbal Reasoning - Mental Ability Questions

In the following question, which one set of letters when sequentially placed at the gaps in the given letter series shall complete it?
_ yzaa _ y _ xy _ aazy _

Introducing a man, Amar says, "His wife is the only daughter of my maternal grandfather". How is the man related to Amar?

Select the related word/letters/number from the given alternatives.
Frog : Amphibian : : Cobra : ?

On BBC World News channel last night they showed an informative program about new innovations in medical imaging, which you would have found interesting.

In a certain code language, “book is tough” is written as “fu la mi”, “tough can easy” is written as “fu muk po” and “easy not book” is written as “ti po la”.What is the code for “tough” in that code language?

If 6@1 = 12, 6@2 = 24 and 9@9 = 162, then find the value of 4@6 = ?

Savage : Civilized :: ____ : ____

In a certain code language, "TREASON" is written as "RKWWINX" and "POULTRY" is written as "CNXHYKT". How is "NUMBER" written in that code language?