Select the letter-cluster from among the given options that can replace the question mark (?) in the following series.

ROM, URJ, XUG, AXD, ?

Select the letter-cluster from among the given options that can replace the question mark (?) in the following series.
RIN, TFR, VCV, ?, ZWD 

Which one set of letter when sequentially placed at the gaps in the given letter series shall complete it?
F __ L __ OWFO __ LO __ __ OLL __ W

Directions : Study the following alphanumeric series carefully and answer the questions given below:

12AIFR                  42 WBOL                             63EOCN                15TVMR               75GYTR

The letters which are attached with the numbers in which at least one is odd digit are arranged according to the ascending orders of their numbers from left to right and then all letters of the words together are arranged in the alphabetical order, then which of the following is the 9^th letter from the right end?

Directions : Study the following alphanumeric series carefully and answer the questions given below:

12AIFR                  42 WBOL                             63EOCN                15TVMR               75GYTR

The words are arranged according to the descending order of the numbers which are attached to them from left to right, then how many alphabets are between the letters of second letter from the left end and seventh letter from the right end?

Directions : Study the following alphanumeric series carefully and answer the questions given below:

12AIFR                  42 WBOL                             63EOCN                15TVMR               75GYTR

How many meaningful words can be formed from the letters of the words which are attached with the numbers in which At least one digit is even digit in the given alphanumeric series?

How many such pairs of letters are there in the word 'BODYGUARD', each of which has as many letters between them in the word as in the English Alphabet?

If a meaningful word can be formed using 1st, 2nd, 4th and 8th letters of CAMPFIRE, what will be the second letter from the left of the newly formed word? If more than one word is formed, mark your answer as X. If no meaningful word can be formed, mark your answer as Z.