Types of Questions in Letter Series - Logical Reasoning (LR) and Data Interpretation

Type - 1

To find out the position of the letter according to the given condition.

Note: If we are moving to the left hand side of any letter that means positions are decreasing and if we are moving towards right hand side of the series that means Positions of the letters are increasing.

If the first half and second half of the alphabet series are Arranged in reverse order, then find out the answers to the given questions:

Q.1. Which letter is 5^th to the right of the 12^th letter from the left-hand side of the series?
Ans: W. In the reversed series (M L K J I H G F E D C B A | Z Y X W V U T S R Q P O N) the 12^th letter from the left is B; moving five places to the right from B gives W.

Q.2. Which letter is 5^th to the left of the 12^th letter from the left-hand side on the series?
Ans: G. In the reversed series the 12^th letter from the left is B. Five places to the left of B is the 7^th letter of the series, which is G.

Q.3. Which letter is the 5^th to the left of the 12^th letter from the right-hand side of the series?
Ans: D. There are 26 letters, so the 12^th from the right is the (27 - 12) = 15^th from the left. Five places to the left of the 15^th is the 10^th from the left. In the reversed series (M L K J I H G F E D C B A | Z Y X W V U T S R Q P O N) the 10^th letter is D.

Q.4. Which letter is 5^th to the right of the 12^th letter from the right-hand side of the series?
Ans: T. The 12^th from the right is the 15^th from the left (27 - 12 = 15). Five places to the right of the 15^th is the 20^th from the left. In the reversed series the 20^th letter is T.

Type - 2 

To find out the next letter of the series.

Find The Letter In Place Of Question Mark (?) In The Series Given Below:
Q.1. B, F, ?, N, R
(a) G
(b) K
(c) J
(d) L
(e) None of The Above
Ans: (c)
Explanation: The letter positions are B(2), F(6), ?, N(14), R(18). These positions increase by 4 each time: 2 → 6 → 10 → 14 → 18. So the missing position is 10, which is J. Therefore option (c) is correct.

Q.2. P, ?, J, G, D, A

(a) Q

(b) N

(c) K

(d) M

(e) None of The Above

Ans: (d)

Explanation: View the sequence as letters moving leftwards in the alphabet: P(16), M(13), J(10), G(7), D(4), A(1). Each term decreases by 3. Hence the missing letter is M (13), so option (d) is correct.

Q.3. ?, E, G, J, N

(a) A   

(b) B

(c) D

(d) Z

(e) None of The Above

Ans: (c)

Explanation: Alphabet positions are ?, E(5), G(7), J(10), N(14). The differences are 5 - x, 7 - 5 = 2, 10 - 7 = 3, 14 - 10 = 4. The increments increase by 1 each time (2, 3, 4), so the first increment must be 1; therefore x = 5 - 1 = 4, which is D. Option (c) is correct.

Q.4. X, F, Y, G, ?, H

(a) Z

(b) A

(c) B

(d) Y

(e) None of The Above

Ans: (a)

Explanation: The series is formed by two interleaved sequences: X, Y, Z (24, 25, 26) and F, G, H (6, 7, 8). The missing term in the first subsequence after Y is Z. Hence option (a) is correct.

Q.5. B, B, A, D, ?, F    

(a) B

(b) A

(c) Z

(d) C

(e) None of The Above 

Ans: (c)

Explanation: There are two alternate subsequences: terms at even positions are B(2), D(4), F(6) - increasing by 2. Terms at odd positions are B(2), A(1), ? - decreasing by 1 with wrap-around (2 → 1 → 26). So the missing odd-term is Z (26). Therefore option (c) is correct.

Type - 3 

Fill in the blank series

Example 1.   a _ c a a _ b c c _ a a b bb _ c c
(a) bbca
(b) abac
(c) bbac
(d) bacb
Ans: (c)
Explanation. We can solve questions of these types by following steps:

• Check the total number of positions: 18 here.
• Look for repeating groups. Observing the pattern around the blanks (_ a a b bb _ c c) suggests blocks where letters appear once, twice and then thrice.
• Rewriting groups as a a b b a a b b a a b b a a b b a a b shows the pattern of single, double and triple repetitions in sequence.
• Filling the blanks to complete that grouped pattern gives the sequence pieces as 'b b a c' for the missing block.

Therefore the correct option is (c) bbac.

Example 2.  a _ b b a a _ b a a _ b a a b _ a a b
(a) abab
(b) baba
(c) abbb
(d) babb
Ans: (c)
Explanation.
We can solve this by following steps:

• The given string has 19 positions. To find a repeating pattern we may consider 16 or 18 positions and inspect plausible group sizes.
• Dividing 16 into groups of 4 yields repeated blocks that fit the observed sequence.
• Completing the pattern gives the missing block as 'abbb', which matches option (c).

Example 3. a _ b c a a _ _ aa b _ a a _ c a a _ c
(a) accbbb
(b) acbcbb
(c) cbcbba
(d) abccbb
Ans: (d)
Explanation. 
We can solve this by following steps:

• Total positions are 20, which can be divided by 2, 4, 5 or 10. Optimal grouping here is by 4.
• Grouping into blocks of 4 shows a repeated pattern: a a b c repeated five times.
• Filling the blanks accordingly leads to the missing letters forming 'abccbb', which is option (d).

Type - 4

Miscellaneous Questions   

In the exam one can also ask questions to make a meaningful word, or by arranging letters in ascending or descending order, or by getting the same gap in between two letters as in the alphabet series.
This can be clearly explained by the following examples:

Example 1. If the letters of the word " BEAUTIFUL" are arranged in Ascending/increasing order. How many letters are there whose position will not change?
(a) 4
(b) 3
(c) 1
(d) 2
Ans: (c)
Explanation:

In ascending order:

Only the letter U remains at the same position after arranging the letters of BEAUTIFUL in alphabetical (ascending) order. Therefore the correct answer is option (c).

Example 2. How many pairs are there in the word "BEAUTIFUL", which have the same number of letters between them as in the alphabet series?
(a) 1
(b) 4
(c) 3
(d) none
Ans: (b)
Explanation:

Check pairs (i, j) where the distance between letters in the word equals their distance in the alphabet. The matching pairs are:

• (E, I) - positions 2 and 6 in the word; alphabet positions 5 and 9 differ by 4, and 6 - 2 = 4.
• (E, L) - positions 2 and 9 in the word; alphabet positions 5 and 12 differ by 7, and 9 - 2 = 7.
• (U, T) - positions 4 and 5 in the word; alphabet positions 21 and 20 differ by 1, and 5 - 4 = 1.
• (I, L) - positions 6 and 9 in the word; alphabet positions 9 and 12 differ by 3, and 9 - 6 = 3.

Thus there are four such pairs. Hence option (b) is correct.

Example 3.With the help of letters " E , S, R , O" each letter used
Ones, how many meaningful words can be formed?
(a) 1
(b) 2
(c) 3
(d) none

Ans. (b)

Explanation. 

Possible meaningful words formed by using each letter once are:

1. ROSE
2. SORE

Both ROSE and SORE are valid words. Therefore the answer is (b) 2.

Note: 

These types of questions are just to check your General intelligence.

Example 4. With the help of the letters "A, D, E, R" each letter used
Ones, how many meaningful words can be formed?
(a) 2
(b) 3
(c) more than 3
(d) none
Ans: (b)
Explanation: Using these letters the meaningful words are: READ, DEAR and DARE. Hence the correct option is (b).