Verbal Reasoning - Mental Ability Questions

If "A" denotes "added to", "B" denotes "divided by", "C" denotes "multiplied by" and "D" denotes "subtracted from", then 154 B 11 C 6 A 6 D 27= ?

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?

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

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

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

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

If 10$25 = 8, 12$25 = 10 then what is the value of 14$53 = ?