Finding the Different Set of Letters

This type of question asks us to identify a pattern or rule that applies to a group of items (in this case, sets of letters) and find the item that does not follow that rule. To solve problems involving letter sets, we often look at the position of each letter in the English alphabet.

Analysing Letter Patterns by Position

Let's assign a numerical position to each letter of the alphabet:

Now let's look at the position of the letters in each given set:

• Set 1: NQT

  N is the 14th letter.

  Q is the 17th letter.

  T is the 20th letter.

  Let's find the difference between consecutive letter positions:

  From N to Q: \(\text{17} - \text{14} = +3\)

  From Q to T: \(\text{20} - \text{17} = +3\)

  The pattern here is adding 3 to the position of the previous letter.

• Set 2: DGJ

  D is the 4th letter.

  G is the 7th letter.

  J is the 10th letter.

  Let's find the difference between consecutive letter positions:

  From D to G: \(\text{7} - \text{4} = +3\)

  From G to J: \(\text{10} - \text{7} = +3\)

  The pattern here is adding 3 to the position of the previous letter.

• Set 3: EHK

  E is the 5th letter.

  H is the 8th letter.

  K is the 11th letter.

  Let's find the difference between consecutive letter positions:

  From E to H: \(\text{8} - \text{5} = +3\)

  From H to K: \(\text{11} - \text{8} = +3\)

  The pattern here is adding 3 to the position of the previous letter.

• Set 4: TQN

  T is the 20th letter.

  Q is the 17th letter.

  N is the 14th letter.

  Let's find the difference between consecutive letter positions:

  From T to Q: \(\text{17} - \text{20} = -3\)

  From Q to N: \(\text{14} - \text{17} = -3\)

  The pattern here is subtracting 3 from the position of the previous letter.

Identifying the Different Set

Comparing the patterns we found:

• NQT follows a +3, +3 pattern.
• DGJ follows a +3, +3 pattern.
• EHK follows a +3, +3 pattern.
• TQN follows a -3, -3 pattern.

Sets NQT, DGJ, and EHK follow the same rule of adding 3 to the alphabetical position of the previous letter to get the next letter. Set TQN follows a different rule, subtracting 3 from the alphabetical position of the previous letter.

Therefore, the set of letters TQN is different from the rest.

Revision Table: Letter Series Patterns

Additional Information: Solving Letter Series Questions

Problems involving letter series or sets of letters in reasoning tests often rely on patterns related to the English alphabet. Here are some common patterns to look for:

• Alphabetical Position: The most common pattern, as seen in this problem, is based on the numerical position of letters (A=1, B=2, etc.).
• Difference in Position: Look for a consistent difference between consecutive letters (like +2, -1, +3, etc.). The difference might be constant, or it might follow its own pattern (e.g., +1, +2, +3).
• Skipping Letters: The pattern might involve skipping a certain number of letters (e.g., skipping 2 letters then 3 letters). This is related to the position difference.
• Vowels and Consonants: Sometimes the pattern relates to whether the letters are vowels (A, E, I, O, U) or consonants.
• Reverse Alphabetical Order: The pattern might involve counting backwards from Z.
• Combinations: More complex patterns can combine position differences with other rules.

Always writing down the alphabet and its positions (or having it handy) can be very helpful when solving these types of letter pattern questions.