Verbal Reasoning - Mental Ability Questions

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

DE, HI, LM,?

Find the next in this series:
YC3, XF6, WI9, ........

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

LT, MS, NR, OQ, ?

If "A" denotes "multiplied by", "B" denotes "subtracted from", "C" denotes "added to" and "D" denotes "divided by", then

8 B 31 C 49 D 7 A 16 = ?

In the following question, select the related number from the given alternatives.
4 : 17 : : 7 : ?

How many squares are there in the square figure ABCD?

Choose the related word/letters/number from the given alternatives. 19 : 6859 : : 21 : ?

In the following question, select the related number from the given alternatives.
243 : 819 : : 163 : ?