Solving Letter Series Completion Problems

This question asks us to find the sequence of letters that completes the given letter series by filling in the blanks. These types of questions often involve identifying a repeating pattern or a logical sequence.

The given letter series is:

C _ _ D _ C _ W _ J C I _ D J C _ W D _

Let's count the number of blanks in the series. Counting carefully from left to right:

C (1), _ (2), _ (3), D (4), _ (5), C (6), _ (7), W (8), _ (9), J (10), C (11), I (12), _ (13), D (14), J (15), C (16), _ (17), W (18), D (19), _ (20).

There are a total of 8 blanks in the series.

We are given options, and the correct option is stated to be I W J I D W I J. This sequence has exactly 8 letters, which matches the number of blanks. This suggests that these 8 letters should fill the 8 blanks sequentially from left to right.

Inserting the Letters into the Blanks

Let's insert the letters I W J I D W I J into the blanks at positions 2, 3, 5, 7, 9, 13, 17, and 20:

Original series positions:

Inserting I W J I D W I J into blanks (positions 2, 3, 5, 7, 9, 13, 17, 20):

The completed series is: C I W D J C I W D J C I W D J C I W D J

Identifying the Pattern

Let's examine the completed series. We can see a repeating block of letters:

• Block 1: C I W D J (Positions 1-5)
• Block 2: C I W D J (Positions 6-10)
• Block 3: C I W D J (Positions 11-15)
• Block 4: C I W D J (Positions 16-20)

The completed series is formed by repeating the block C I W D J exactly four times.

The letters inserted from the option I W J I D W I J successfully filled the blanks (at positions 2, 3, 5, 7, 9, 13, 17, 20) to create this consistent repeating pattern.

Conclusion

The letters that complete the series to form the repeating pattern C I W D J are I W J I D W I J.

The completed series demonstrates a clear and consistent pattern based on a repeating five-letter block. This confirms that the sequence I W J I D W I J is the correct set of letters to fill the blanks sequentially.

Revision Table: Letter Series Patterns

Additional Information on Letter Series Reasoning

Letter series questions are a common type of logical reasoning problem. They test your ability to identify rules, patterns, or sequences governing the arrangement of letters. To solve them effectively, consider the following approaches:

• Look for Repeating Blocks: This is the most frequent pattern. Try to break the series into equal segments and see if any segment repeats.
• Check Alphabetical Order: See if letters are in forward or reverse alphabetical order, or if they skip letters with a constant difference.
• Analyze Letter Positions: The position of letters in the alphabet (A=1, B=2, etc.) might follow a mathematical sequence.
• Look at Adjacent Letters: The relationship between a letter and the one next to it might follow a rule (e.g., consecutive letters, letters skipping one).
• Divide the Series: Splitting the series into halves or smaller groups might reveal patterns within those parts.
• Consider Alternating Patterns: Sometimes, letters at odd positions follow one rule, and letters at even positions follow another.

Systematic checking of these possibilities usually helps in finding the hidden pattern and completing the series accurately.