Verbal Reasoning - Mental Ability Questions

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. Select the correct alternative from the given ones that will complete the series.

HOT, GMQ, FKN, EIK, ?

Select the number which can be placed in the place of ?

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

YXW, TSR, NML, ?

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

nature, ensure, tense, spent, spurn, ?

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

?, flight lieutenant, squadron leader, wing commander

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

_ABBI_R_B_IT_AB_IT

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

XT, YU, BX, GC, ?