Select the combination of letters that when sequentially placed in the blanks of the given series will complete the series.
C _ B N _ _ V_ _ H C _ B _ H

Question

Select the combination of letters that when sequentially placed in the blanks of the given series will complete the series.TK_TKT_P_K_KPTK_K_TK

Prepp Team · Accepted Answer

Understanding Letter Series Completion

Letter series completion is a common type of question in logical reasoning tests. These questions require you to identify the pattern in a given sequence of letters and then use that pattern to fill in the missing letters.

The given series is:

TK_TKT_P_K_KPTK_K_TK

We need to select the combination of letters that correctly fills the blanks to complete the series based on a logical pattern.

Analyzing the Options and Finding the Pattern

Let's examine the options provided. Each option gives a sequence of six letters to fill the six blanks in the series. We will test the option that leads to a consistent pattern.

The correct answer is given as Option 2: P, K, T, T, T, P.

Let's insert these letters into the blanks in the given series:

Original series with blanks:

T K _ T K T _ P _ K _ K P T K _ K _ T K

Inserting the letters P, K, T, T, T, P sequentially into the blanks:

Blank 1 (after TK): Insert P → TKPTKT_P_K_KPTK_K_TK
Blank 2 (after TKT): Insert K → TKPTKTKP_K_KPTK_K_TK
Blank 3 (after KP): Insert T → TKPTKTKPTK_KPTK_K_TK
Blank 4 (after KT): Insert T → TKPTKTKPTKTKPTK_K_TK
Blank 5 (after KPTK): Insert T → TKPTKTKPTKTKPTKTK_TK
Blank 6 (after KT): Insert P → TKPTKTKPTKTKPTKTKPTK

The completed series is:

TKPTKTKPTKTKPTKTKPTK

Now, let's look closely at this completed series to identify a repeating pattern. Let's try to divide the series into potential repeating units:

TKPTK TKPTK TKPTK TKPTK TK

Upon careful observation, we can see that the sequence TKPTK repeats multiple times, followed by TK at the end.

The first five letters are TKPTK.
The next five letters are TKPTK (from position 6 to 10).
The next five letters are TKPTK (from position 11 to 15).
The next five letters are TKPTK (from position 16 to 20).
The last two letters are TK (from position 21 to 22).

The pattern identified is the repetition of the block TKPTK, appearing 4 times, followed by the initial two letters TK.

The sequence of letters P, K, T, T, T, P from Option 2 successfully completes the series such that it follows this clear repeating pattern.

Step-by-Step Verification

Let's map the inserted letters back to the blanks and see how they fit the pattern:

Series with blanks: T K _ T K T _ P _ K _ K P T K _ K _ T K

Pattern blocks: (TKPTK) (TKPTK) (TKPTK) (TKPTK) (TK)

Mapping blanks to pattern positions:

Blank 1 is the 3rd letter of the 1st block (TKPTK) → P
Blank 2 is the 3rd letter of the 2nd block (TKPTK)? No, let's re-index based on the original series structure.

Let's write the completed series and indicate where the original blanks were:

T K P T K T K P T K T K P T K T K P T K

Original series: T K _ T K T _ P _ K _ K P T K _ K _ T K

Comparing these two, the letters filling the blanks are:

Blank 1 (position 3): P
Blank 2 (position 7): K
Blank 3 (position 9): T
Blank 4 (position 11): T
Blank 5 (position 16): T
Blank 6 (position 18): P

The sequence of letters inserted is P, K, T, T, T, P. This matches the sequence provided in Option 2.

Therefore, Option 2 correctly completes the letter series based on the repeating pattern TKPTK followed by TK.

Blank No.	Position in Series	Inserted Letter (from Option 2)	Completed Series with Inserted Letter
1	3	P	TKPTKT_P_K_KPTK_K_TK
2	7	K	TKPTKTKP_K_KPTK_K_TK
3	9	T	TKPTKTKPTK_KPTK_K_TK
4	11	T	TKPTKTKPTKTKPTK_K_TK
5	16	T	TKPTKTKPTKTKPTKTK_TK
6	18	P	TKPTKTKPTKTKPTKTKPTK

Revision Table: Key Concepts in Letter Series

Concept	Description	Example Pattern Types
Identifying the Pattern	Look for repeating blocks, alternating sequences, or sequences based on alphabetical order (forward or backward), skip patterns, or combinations.	Repeating block (e.g., ABC ABC), Alternating (e.g., ABAB), Alphabetical skips (e.g., A C E G), Mixed patterns.
Counting and Grouping	Count the total number of letters (including blanks). Try grouping the letters into equal parts to find repeating units. The total length is often a multiple of the repeating unit's length.	Series length 16, try groups of 4 or 8. Series length 22 (like this one), grouping might reveal a slightly irregular end or start.
Testing Options	Once a potential pattern or group length is suspected, insert letters from the options into the blanks and check if the pattern holds true for the completed series.	Systematically insert letters from Option 1, check pattern. Then Option 2, etc.
Blank Positions	Pay attention to the positions of the blanks as they dictate which part of the potential pattern is missing.	If blanks are at regular intervals, it strongly suggests a repeating block.

Additional Information: Strategies for Solving Letter Series

Solving letter series problems effectively requires a systematic approach. Here are some strategies:

Count the total letters: This helps in deciding the possible length of the repeating unit. Divide the total length by small integers (2, 3, 4, 5, etc.) to find potential group sizes.
Scan the series for repeating segments: Even with blanks, you might see parts of a pattern. In our example, 'TK' appears multiple times.
Look at the letters present: Note the distinct letters used in the series (here, T, K, P). This limits the possibilities for the blanks.
Test the options systematically: This is crucial. Insert the letters from each option one by one into the blanks and write down the resulting series.
Analyze the completed series: Once an option's letters are inserted, look for the pattern. Does a block repeat? Is there an alternating sequence? Is there a progression based on the alphabet?
Don't force a pattern: The pattern should be clear and consistent throughout the completed series (with allowances for a partial final block sometimes, as seen in this question).
Consider different pattern types: Be open to various patterns – simple repetition, alternating patterns, patterns involving skipping letters based on alphabetical order, or even reverse alphabetical order.