What would come at question (?) mark place?

The missing term of the series is

A2, C5, E8, G11, _________

Find the missing term in given series:

1, 9, 25, 49, 81, ?, 169

If English alphabets are written in the backward order, then which is the 7th letter to the right of K?

Which option will replace the question mark in the given series:

BB0, EC2, HE3, KG4, NK3, ?

Which of the following characters, when placed at the sign of interrogation (?) will complete the given pattern?

In the given letter series, some of the letters are missing which are given in that order as one of the following alternatives. Choose the correct alternative.

_a_b_abaa_bab_abb