Letter Cluster Series Reasoning: Three-Letter Pattern Questions with Tricks and Answers for SSC

A letter cluster series gives groups of 2 to 4 letters, such as ABC, DEF, GHI, and you find the missing cluster. The easy way is the column method: treat the first letters, the second letters and the third letters as three separate letter series. These letter cluster series tricks for SSC explain the method and solve the popular patterns.

The Column Method

1. Write the clusters one below the other so that the same positions fall in one column.
2. Find the pattern of each column separately (the step of the 1st, 2nd and 3rd letters).
3. Apply the patterns to the missing cluster.

Common Patterns

Solved Examples

Example 1. BGL, CHM, DIN, ?
Each column moves +1: B, C, D, E; G, H, I, J; L, M, N, O. The next is EJO.

Example 2. ACE, FHJ, KMO, ?
The first letters A, F, K go +5, so the next is P. Inside a cluster the step is +2. The next cluster is PRT.

Example 3. AEI, BFJ, CGK, ?
Each column moves +1. The next is DHL.

Example 4. ZYX, WVU, TSR, ?
The letters go backward by one, and the next cluster continues the reverse alphabet: QPO.

Example 5. PQR, STU, VWX, ?
The alphabet continues, and after X it wraps around: YZA.

Tips

• Write the numbers under the letters if the pattern is not clear.
• Check whether the first letters of the clusters make their own series.
• Do not expect all columns to have the same step.

Quick Tips

• Use the column method.
• Check the step of each column separately.
• Wrap around after Z.
• Write the numbers under the letters.

Quick Revision Points

• Treat each position as a separate series.
• The columns can have different steps.
• After Z comes A.
• Reverse clusters go backward.
• Check the first letters as a series.

Practice Questions With Answers

1. ABC, DEF, GHI, ?
   Answer: JKL
2. BGL, CHM, DIN, ?
   Answer: EJO
3. ACE, FHJ, KMO, ?
   Answer: PRT
4. AEI, BFJ, CGK, ?
   Answer: DHL
5. ABD, BCE, CDF, ?
   Answer: DEG
6. ZYX, WVU, TSR, ?
   Answer: QPO
7. AAB, BBC, CCD, ?
   Answer: DDE
8. PQR, STU, VWX, ?
   Answer: YZA
9. DAB, EBC, FCD, ?
   Answer: GDE
10. MNO, PQR, STU, ?
    Answer: VWX

How to Practise This Chapter

Practise 10 questions every day and write the steps on paper. Then attempt timed sets from our practice papers and the previous year papers page. See all topics on the Verbal Reasoning notes page, read the previous topic Letter Series and the next topic Letter Coding Decoding. Learn the letter positions from the Alphabet Test note first.

Frequently Asked Questions

What is a letter cluster series?

It is a series of groups of letters in which you find the missing group.

What is the column method?

You treat the 1st, 2nd and 3rd letters of the clusters as three separate series.

What if the columns have different steps?

Find the step of each column separately.

What comes after XYZ in a series?

The series wraps around and continues with A, B, C.

What is the next cluster in ABC, DEF, GHI?

JKL.

What is the next cluster in BGL, CHM, DIN?

EJO.

Is this topic asked in SSC exams?

Yes. Letter cluster series are asked in SSC CGL and CHSL.

How much time should I take?

About 40 seconds.

What are the common mistakes?

Not checking each column separately.

How can I practise?

Make your own clusters and write their patterns.

What if the pattern is not clear?

Change the letters into numbers.

How is it different from letter series?

It has groups of letters, so you find patterns in columns.