These questions are based on arrangements of symbols, letters and numbers.
Questions may be asked as

Count how many specific symbols or vowels in the arrangements.

Count how many specific symbols (or letter or number) is followed or preceded by another symbols or vowels.

Which element (symbol letter or number) is specific position from left end or right end.

Question like which of the following is fourth to the left of the twelfth from the left end.

Four of the following five are alike in a certain way based of their position in the arrangements, find the odd one.

If all the symbols are removed from the arrangements, which elements will be third to the left of eleventh elements from the left end.
Rules

Right from Right => Minus (Subtract)

Left from Left => Minus (Subtract)

Right from Left => Plus (Add)

Left from Right => Plus (Add)
Sample Question
Study the following arrangement carefully and answer the questions given below:
T % R Q 2 6 W $ L X 1 A 8 Z * B 3 # 7 E 8 4 @ M 5 K % D 9 & U

Which of the following is the twelfth to the left of the twentieth from the left end of the above arrangement?
Follow Rule 2: Subtract.
20  12 = 8^{th} from Left end (Because mentioned as left end in question)
So count 8th element from left end you will find $
Answer is $

If all the numbers in the above arrangement are dropped, which of the following will be the eleventh from the right end?
Just strike the numbers in the arrangements
< Right End
T % R Q 2 6 W $ L X 1 A 8 Z * B 3 # 7 E 8 4 @ M 5 K % D 9 & U
count eleventh elements from right end (Leave strike numbers).
You will find *
Answer is *

How many such consonants are there in the above arrangement each of which is immediately preceded by a consonant and also immediately followedby a number.
Just remember that preceded means before specific element and followed means after specific element. consonants are alphabets except a, e, i, o, u.
For example,
In ABC, A is preceded element of B and C is following element of B.
In the given arrangement we want to find the sequence like bc1 or rp5 etc...
T % R Q 2 6 W $ L X 1 A 8 Z * B 3 # 7 E 8 4 @ M 5 K % D 9 & U
so there are only two such consonant are present (Q and X)
Answer is Two

How many such vowels are there in the above arrangement of which immediately preceded by a symbol or immediately followed by a symbol or both.
In this question we want to find vowels (A, E, I, O, U) with a symbol before or symbol after vowels or vowels in the middle of two symbol on either side.
such as
$A or
A% or
#A*
T % R Q 2 6 W $ L X 1 A 8 Z * B 3 # 7 E 8 4 @ M 5 K % D 9 & U
Answer is One (U)

How many such symbols are there in the above arrangement, each of which is immediately preceded by a number and also immediately followedby a letter.
In this question we want to find the symbols (like %, #, $, *) which is placed after a number and before an alphabetic letter (consonant or vowels). like 7$B
T % R Q 2 6 W $ L X 1 A 8 Z * B 3 # 7 E 8 4 @ M 5 K % D 9 & U
Answer is One (@).

Which of the following is the seventh to the right of the fourth from the left endin the above arrangement.
In this question right and left => Add
7 + 4 = 11 from left end.
so count 11^{th} element form left end
Left end>
T % R Q 2 6 W $ L X 1 A 8 Z * B 3 # 7 E 8 4 @ M 5 K % D 9 & U
11th element is 1
Answer is 1

If all the letters are replaced with next letter in alphabetic series then how many vowels will be present after replacing the arrangement.
Replace every letter with next alphabetic letter, for example A to B, U to V, Z to A, M to N...
T % R Q 2 6 W $ L X 1 A 8 Z * B 3 # 7 E 8 4 @ M 5 K % D 9 & U
we will get
U % S R 2 6 X $ M Y 1 B 8 A * C 3 # 7 F 8 4 @ N 5 L % E 9 & V
There are three vowels in the converted arrangement.
Answer is 3

How many such numbers are there in the above arrangement each of which is immediately preceded by a consonant and also immediately followed by a symbol.
In this question we want to find the number which is placed after a consonant and before a symbol (like @, %, #, &,...). like B7$
T % R Q 2 6 W $ L X 1 A 8 Z * B 3 # 7 E 8 4 @ M 5 K % D 9 & U
Answer is Three.

Four of the following are alike in a certain way based on their positions in the above arrangement and so form a group. Which is the one that does not belong to that group.1) 2WX 2) AZ3 3) 8@5 4) R2$ 5) 78M
First find the sequence of element in the answers.
For choice 1) 2WX
T % R Q 2 6 W $ L X 1 A 8 Z * B 3 # 7 E 8 4 @ M 5 K % D 9 & U
that is sequence is fifth element and then seventh element and then tenth element. So sequence is, first element position, then element position + 2 and next is element position +3
check for other choice you will find the answer...
Have you got. Ok answer is 3) 8@5 which is not following this sequence in the given answers.
Answer is 3

If Q6:WL :: AZ:?
Find the letter in Q, 6, and then W, L
T % R Q 2 6 W $ L X 1 A 8 Z * B 3 # 7 E 8 4 @ M 5 K % D 9 & U
Now find A, Z. In the same sequence you will find * and then 3
T % R Q 2 6 W $ L X 1 A 8 Z* B 3 # 7 E 8 4 @ M 5 K % D 9 & U
so the answer is *3