How many such pairs of letters are there in the word MEDIOCRE each of which has as many letters between them in the English alphabet series? 

Find the missing (?) in the series.
NA, PC, RE, TG, ?, XK, ZM

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

A series is given, a term is missing in series. Choose the correct alternative from the given ones that will complete the series.
I, V, ? , L

Direction: Answer the questions given below referring to the following arrangement.
2 L P 3 R * J @ C O 7 N I # 4 Q A B 6 $ M = D 5 K

What will come in the place of the question marks (?) in the following series based on the above arrangement?
P3R, @CO, I#4, B6$, ?

Direction: Answer the questions given below referring to the following arrangement.
2 L P 3 R * J @ C O 7 N I # 4 Q A B 6 $ M = D 5 K

If the above series is re-arranged in the reverse order, which will be the eleventh to the left of the sixteenth elements from the left end?

Complete the following alphabet series?
SAB, ?, QCD, PDD, OEF, NFF

Complete the following alphabet series?
BAZ, DBY, FCX, ?