If the first and second letters in the word ' COMMUNICATIONS' were interchanged, also the 3rd and the 4th letters, the 5th and 6th letters and so on, which letter would be the 10th letter counting from your right?

According to given question,
D(4) ? H(8)
E(5) ? J(10)
On the basis of above relationship , we get the value of K
Therefore, K(11) ? V(22)

Coding of letters is based on the structure of the word. Logic of coding is very simple. Observe the word and the codes. It gives us following information:
If the word consists of four letters,
(i) and consonants occupy places at extreme ends only, then those consonants are replaced by [5] while vowels are replaced by either [20] (if both the vowels are same) or [15] (if both the vowels are different).
(ii) and the vowels occupy the second and the fourth places only then those vowels are replaced by [25], while the consonants are replaced by [5].
(iii) and the vowels occupy the first and third places only then those vowels are replaced by [30], while the consonants are replaced by [5].
If the word consists of three letters,
(i) and the vowels occupy places at extreme ends only then those vowels are replaced by [0], while the consonant is replaced by [5].
(ii) and the consonants occupy places at extreme ends only then those consonants are replaced by [5], while the vowel is replaced by [10].
Thus, in each and every case consonants are coded as [5] but numeric value assigned to vowels varies according to the position of vowels in a particular word.

The first letter is coded as two letters: the first remains unchanged and the second two letters forward as in English alphabet. The second, fourth, fifth and sixth letters are coded as two letters forward while the third letter is coded as three letters forward as in English alphabet. The last letter remains unchanged.

Divide the word into two groups of five letters each. The first five letters are in group I and the last five letters are in group II. Now, for its coding the middle letters remain unchanged. While the letters in each group change their position as 1 ? 3, 2 ? 5, 3 ? 4, 4 ? 2 and 5 ? 1.

E L E P H E A N T
5 7 5 8 9 1 4 3
L E A P
7 5 1 8

The pattern is given in the question as below.
E ? (i)
R ? (ii)
D ? (iii)
I ? (iv)
S ? (v)
P ? (vi)
Try to form a word by arranging the letters for all given option one by one.
Arranging to given word in question ,we get the meaningful word -
S ? (v)
P ? (vi)
I ? (iv)
D ? (iii)
E ? (i)
R ? (ii)
Hence , the required answer will be SPIDER.

According to given question,
L ? b , X ? a , P ? e , Z ? s , J ? p , Y ? r , Q ? h , M ? i , N ? g , B ? t
Replace the each capital from given relationship for Z B Y X M N Q B , We will get
Z ? s
B ? t
Y ? r
X ? a
M ? i
N ? g
Q ? h
B ? t

According to given question,
A ? @ , B ? # , C ? $ , D ? % , E ? ^ , M ? & , N ? * , O ? ? , S ? ? , R ? ? , U ? ?
Replace the each capital from given relationship for # ? @ ? %, We will get
# ? B
? ? O
@ ? A
?? R
% ? D
Hence , the required answer will be BOARD.

According to given question,
A ? @ , C ? # , D ? $ , E ? % , G ? = , H ? ^ , K ? & , L ? * , M ? ? , N ? ? , O ? ? , S ? ?
Replace the each capital from given relationship for ^ ? ? @ =%, We will get
^ ? H
? ? O
? ? M
@ ? A
=? G
% ? E
Hence , the required answer will be HOMAGE.

According to given question,
A ? ! , B ? @ , C ? # , D ? $ , E ? % , F ? ^ , G ? & , H ? * , I ? + , O ? = , P ? ? , R ? ? , S ? ? , T ? ? , U ? ?
Replace the each capital from given relationship for FIGHT, We will get
^ ? F
+ ? I
& ? G
* ? H
? ? T
Hence , the required answer will be ^ + & * ?.