The forces that work on the surface of the earth are

Select the combination of letters that, when sequentially places in the gaps of the given letter series will complete the series.

What should come in place of the question mark (?) in the given series based on the English alphabetical order?

RJK, PMI, NPG, LSE, ?

In a certain code language,

A # B means A is the sister of B.

A @ B means A is the son of B.

A & B means A is the wife of B.

What should come in place of ‘?’ in the given series?

16, 21, ?, 43, 60, 81, 106

GPK : MSI : : RHT : VKT :: IDW : ?

What should come in place of? in the given series based on the English alphabetical order?

TEO, RCM, PAK, NYI, ?

Select the missing number from the given series.

41, 83, 168, 339,?

Select the figure that will come next in the following figure-series. 

In a certain code language, 'rivers trees grass' is coded as '22 44 66' and trees clouds birds' is coded as '44 99 88'.