SSC CGL Tier 1

Alphabet Series

Alphabet Series is a topic where a sequence of letters or letter groups is given and you have to find the missing term or the next term by identifying the pattern. To solve these questions quickly you must know the position of each letter in the English alphabet.
 

Position of Letters - Must Memorize:
 

A=1, B=2, C=3, D=4, E=5, F=6, G=7, H=8, I=9, J=10, K=11, L=12, M=13, N=14, O=15, P=16, Q=17, R=18, S=19, T=20, U=21, V=22, W=23, X=24, Y=25, Z=26
 

Reverse Position of Letters - Also Important:
 

A=26, B=25, C=24, D=23, E=22, F=21, G=20, H=19, I=18, J=17, K=16, L=15, M=14, N=13, O=12, P=11, Q=10, R=9, S=8, T=7, U=6, V=5, W=4, X=3, Y=2, Z=1
 

Types of Alphabet Series in SSC CGL:
 

1. Single Letter Series A sequence of individual letters with a pattern.
 

Example: B, E, H, K, N, ? 
Answer: Q 
(Each letter increases by 3 positions. B+3=E, E+3=H, H+3=K, K+3=N, N+3=Q)
 

2. Letter Group Series Groups of letters follow a pattern.
 

Example: ABC, DEF, GHI, ?
Answer: JKL 
(Each group has 3 consecutive letters, starting where the previous group ended)
 

3. Missing Letter Series A letter is missing from the middle of the series.
 

Example: A, C, ?, G, I
Answer: E 
(Alternate letters of the alphabet - skip one letter each time)

 

4. Mixed Pattern Series Letters skip positions based on increasing or decreasing differences.

 

Example: Z, X, U, Q, ?
Answer: L 
(Differences are 2, 3, 4, 5. So Q - 5 = L. Z-2=X, X-3=U, U-4=Q, Q-5=L)

 

Important Tricks to Solve Alphabet Series:
 

Trick 1 - EJOTY Rule: 
E=5, J=10, O=15, T=20, Y=25 
These are positions of multiples of 5. Memorize these to quickly find positions.
 

Trick 2 - Opposite Letters: 
A-Z, B-Y, C-X, D-W, E-V, F-U, G-T, H-S, I-R, J-Q, K-P, L-O, M-N 
Sum of opposite letter positions is always 27.
 

Trick 3 - Find the difference: 
Always write the position numbers of given letters and find the difference between consecutive terms.
 

How to Solve Alphabet Series Questions:

Step 1 - Write the position numbers of all given letters. 
Step 2 - Find the differences between consecutive positions. 
Step 3 - Identify the pattern in differences (constant, increasing, decreasing). 
Step 4 - Apply the same pattern to find the missing term. 
Step 5 - Convert the position number back to the letter.

 

Common Patterns in SSC CGL:

 

  • Constant difference: B, D, F, H (difference of 2 each time)
  • Increasing difference: A, B, D, G, K (difference 1, 2, 3, 4)
  • Decreasing difference: Z, X, V, T (difference of 2, going backward)
  • Alternate letters: A, C, E, G, I
  • Skip 2 letters: A, D, G, J, M
  • Reverse series: Z, Y, X, W, V

 

Important Tips:

 

  • Memorize position of all 26 letters before the exam
  • Practice the EJOTY trick daily - it saves time
  • Always check both forward and backward direction of the series
  • In group series, check if the gap between groups is constant
  • Attempt at least 15 questions daily from this topic
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