Verbal Reasoning - Mental Ability Questions

Which set of letters when sequentially placed at the gaps in the given letter series shall complete it?

AB_AB_AA_BB_

Select the missing number?

Find the missing term in the following question:-

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

HTC, LXG, PBK, TFO, ?

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

AN, CQ, ET, ?, IZ

From the given answer figures, select the one in which the question figure is hidden/embedded.

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

Smart, Aspire, Castle, Abysmal, Accost, ?

From the given alternative words, select the word which cannot be formed using the letters of the given word:

ENVIRONMENT