Solving Letter Series and Finding the Pattern

This question asks us to identify the pattern in the given series of letter pairs and find the missing term. The series is: AF, CH, EJ, GL, ?

Let's analyze the pattern by looking at the first letter and the second letter of each pair separately.

Analyzing the First Letters in the Series

The first letters in the series are A, C, E, G. Let's look at their position in the English alphabet:

• A is the 1st letter.
• C is the 3rd letter.
• E is the 5th letter.
• G is the 7th letter.

We can see a clear pattern here. The position numbers are increasing by 2 each time (1, 3, 5, 7). This means the first letters are moving forward by two positions in the alphabet for each subsequent term.

Following this pattern, the next first letter should be the letter that is 2 positions after G. G is the 7th letter, so the next letter will be the 7 + 2 = 9th letter, which is I.

Analyzing the Second Letters in the Series

Now let's look at the second letters in the series: F, H, J, L. Let's look at their position in the English alphabet:

• F is the 6th letter.
• H is the 8th letter.
• J is the 10th letter.
• L is the 12th letter.

Similar to the first letters, the position numbers for the second letters are also increasing by 2 each time (6, 8, 10, 12). This means the second letters are also moving forward by two positions in the alphabet for each subsequent term.

Following this pattern, the next second letter should be the letter that is 2 positions after L. L is the 12th letter, so the next letter will be the 12 + 2 = 14th letter, which is N.

Combining the Patterns to Find the Missing Term

By combining the next first letter (I) and the next second letter (N), the missing term in the series is IN.

Let's summarize the pattern:

• First letter pattern: A (+2) → C (+2) → E (+2) → G (+2) → I
• Second letter pattern: F (+2) → H (+2) → J (+2) → L (+2) → N

The next term in the series is IN.

Checking the Options

Comparing our derived term 'IN' with the given options, we find that option 3 is IN.

Revision Table: Letter Series Patterns

Understanding different types of letter series patterns is key to solving these questions. Common patterns include:

• Alphabetical order with a fixed gap (like in this question, +2).
• Alphabetical order with increasing or decreasing gaps (+1, +2, +3, ... or -1, -2, -3, ...).
• Alternating patterns (different patterns for alternate terms or letters).
• Patterns based on letter positions (e.g., sum or difference of positions).
• Patterns involving vowels or consonants.

Additional Information on Letter Reasoning

Letter reasoning questions are common in aptitude tests. They test your ability to identify sequences and rules based on the order of letters in the alphabet. To improve your skills, practice identifying simple arithmetic progressions (like adding a constant number of positions), geometric progressions, alternating series, and position-based logic. Knowing the position of each letter (A=1, B=2, ..., Z=26) quickly can be very helpful.