Verbal Reasoning - Mental Ability Questions

A series is given with one term missing. Choose the correct alternative from the given ones that will complete the series.
DP, EY, FJ, ?

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

PNR, RQV, TTZ, ?, XZH

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

p_r_s_q_p_rs

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

yes, rain, alive, subtle, ?

In the following question, from the given alternative words, select the word which cannot be formed using the letters of the given word.
Legislator

In a certain code language, if SIGN is coded as 8367 and DIRECT is coded as 134259, then SIREN will be coded as

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

JI, LK, NM, ?

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

64, 100, 169, 289, ?