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.

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)

we can write the given word COMMUNICATIONS as -
C ? 1
O ? 2
M ? 3
M ? 4
U ? 5
N ? 6
I ? 7
C ? 8
A ? 9
T ? 10
I ? 11
O ? 12
N ? 13
S ? 14
After rearrangement , The letter N will be the tenth letter counting from right .

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 ^ + & * ?.

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 DEAR , We will get
D ? $
E ? %
A ? !
R ? ?
Hence , the required answer will be $ % ! ?.

According to given question,
@ ? A
# ? R
$ ? G
% ? U
& ? E
and,
? ? S
? ? O
? ? L
? ? V
& ? E
Replace the each capital from given relationship for ? @ $% &? ?, We will get
? ? V
@ ? A
$ ? G
% ? U
& ? E
? ? L
? ? Y
Hence , the required answer will be VAGUELY .