Verbal Reasoning - Mental Ability Questions

Select the related word/letters/numbers from the given alternatives:

12 : 54 :: 15 : ?

Select the related word/letters/numbers from the given alternatives:

12 : 39 :: 15 : ?

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

PLUMBER : REBMULP : : ? : LABREV

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

ZY : CD : : SR : ?

In the following question, select the related word pair from the given alternatives.

Gold : Jewellery : : ? : ?

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

AEIM:BFJN::CGKO:?

Select the related letters from the given alternatives.

ILN : FIK :: RUW : ?

Which number will fit both the series of numbers?

Series A : 1, 4, 9,...
Series B : 1, 8, 27,...