Verbal Reasoning - Mental Ability Questions

Select the related word/letters/number from the given alternatives.
841 : 29 :: 289 : ?

If '+' means '÷', '−' means '×' , '÷' means '+' and '×' means '−' , then 36×12+4÷6+2−3= ?

In a certain code language, '+' represents 'x', '-' represents '+', 'x' represents '÷' and '÷' represents '-'. What is the answer to the following question?

12 x 6 ÷ 5 + 4 = ?

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

Troposphere, Stratosphere, Mesosphere, ?

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

VW, XU, ZS, BQ, ?

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

30, 62, 189, 760, ?

In the following question, select the related letter from the given alternatives.
DE : O : : AF : ?

RHYTHM is related to MUSIC in the same way as DESIGN is related to