Finding the Missing Term in the Letter Series

The question asks us to identify the missing term in the given letter series: AZ, GT, MN, ?, YB.

To solve letter series problems, we usually look for patterns in the positions of the letters within the alphabet. We can analyze the first letter of each term separately and the second letter of each term separately.

Analyzing the First Letters of the Series

Let's look at the first letters of each term:

• A
• G
• M
• ?
• Y

Let's find the position of each letter in the English alphabet (A=1, B=2, ..., Z=26):

• A is the 1st letter.
• G is the 7th letter.
• M is the 13th letter.
• Y is the 25th letter.

Now, let's see the difference in positions between consecutive first letters:

• From A (1) to G (7): $\text{7 - 1 = 6}$
• From G (7) to M (13): $\text{13 - 7 = 6}$

It appears there is a consistent addition of 6 to the position of the first letter to get the position of the next first letter. Following this pattern, the first letter of the missing term should be:

• From M (13), add 6: $\text{13 + 6 = 19}$

The 19th letter of the alphabet is S. Let's check if adding 6 from S (19) leads to Y (25):

• From S (19) to Y (25): $\text{25 - 19 = 6}$

Yes, the pattern holds for the first letters. The first letter of the missing term is S.

Analyzing the Second Letters of the Series

Now, let's look at the second letters of each term:

• Z
• T
• N
• ?
• B

Let's find the position of each letter in the English alphabet (A=1, B=2, ..., Z=26):

• Z is the 26th letter.
• T is the 20th letter.
• N is the 14th letter.
• B is the 2nd letter.

Now, let's see the difference in positions between consecutive second letters:

• From Z (26) to T (20): $\text{20 - 26 = -6}$ (decreasing by 6)
• From T (20) to N (14): $\text{14 - 20 = -6}$ (decreasing by 6)

It appears there is a consistent subtraction of 6 from the position of the second letter to get the position of the next second letter. Following this pattern, the second letter of the missing term should be:

• From N (14), subtract 6: $\text{14 - 6 = 8}$

The 8th letter of the alphabet is H. Let's check if subtracting 6 from H (8) leads to B (2):

• From H (8) to B (2): $\text{2 - 8 = -6}$ (decreasing by 6)

Yes, the pattern holds for the second letters. The second letter of the missing term is H.

Combining the Patterns to Find the Missing Term

The first letter of the missing term is S, and the second letter is H. Therefore, the missing term in the series is SH.

Comparing with the Options

Let's check the given options:

1. JH
2. TS
3. SK
4. SH

Our calculated missing term, SH, matches Option 4.

Revision Table for Letter Series Patterns

Pattern for first letters: Add 6 to the position of the previous first letter (1 > 7 > 13 > 19 > 25). Pattern for second letters: Subtract 6 from the position of the previous second letter (26 > 20 > 14 > 8 > 2).

Additional Information on Letter Series Questions

Letter series questions are common in reasoning and aptitude tests. They test your ability to identify logical patterns in sequences of letters.

Common types of patterns in letter series include:

• Adding or subtracting a fixed number to the letter positions.
• Adding or subtracting an increasing or decreasing number to the letter positions.
• Alternating patterns for different parts of the term (like in this question, +6 for the first letter, -6 for the second).
• Patterns based on vowels and consonants.
• Patterns based on reverse alphabetical order.

Solving these questions requires careful observation and systematic analysis of the sequence.