Which letter-cluster will replace the question mark (?) to complete the given series? SPIN, RQJM, ?, PSLK, OTMJ
QRKL
Finding the Missing Letter Cluster in the Series
The question asks us to identify the letter cluster that should replace the question mark (?) in the given series: SPIN, RQJM, ?, PSLK, OTMJ.
To solve letter series questions like this, we need to analyze the pattern or rule that connects consecutive terms in the series. We look at how each letter's position changes from one cluster to the next based on its position in the English alphabet (A=1, B=2, ..., Z=26).
Analyzing the Pattern Between Terms
Let's examine the change from the first term (SPIN) to the second term (RQJM):
- First letter: S (19) to R (18) - Change of \(18 - 19 = -1\)
- Second letter: P (16) to Q (17) - Change of \(17 - 16 = +1\)
- Third letter: I (9) to J (10) - Change of \(10 - 9 = +1\)
- Fourth letter: N (14) to M (13) - Change of \(13 - 14 = -1\)
So, the pattern from SPIN to RQJM is a letter shift of (-1, +1, +1, -1) applied to the positions of the letters.
Let's check if this pattern is consistent by looking at the last two terms given: PSLK and OTMJ.
- First letter: P (16) to O (15) - Change of \(15 - 16 = -1\)
- Second letter: S (19) to T (20) - Change of \(20 - 19 = +1\)
- Third letter: L (12) to M (13) - Change of \(13 - 12 = +1\)
- Fourth letter: K (11) to J (10) - Change of \(10 - 11 = -1\)
The pattern from PSLK to OTMJ is also (-1, +1, +1, -1). This indicates that this specific letter shift pattern is applied consistently from one term to the next throughout the series.
Applying the Pattern to Find the Missing Term
The missing term is located between RQJM and PSLK. Since the pattern is consistently applied to each term to get the next one, we should apply the pattern (-1, +1, +1, -1) to the letters of RQJM to find the missing term.
Let's apply the shift to RQJM:
- First letter: R (18). Applying -1 shift: \(18 - 1 = 17\). The 17th letter is Q.
- Second letter: Q (17). Applying +1 shift: \(17 + 1 = 18\). The 18th letter is R.
- Third letter: J (10). Applying +1 shift: \(10 + 1 = 11\). The 11th letter is K.
- Fourth letter: M (13). Applying -1 shift: \(13 - 1 = 12\). The 12th letter is L.
Applying the pattern (-1, +1, +1, -1) to RQJM gives the letter cluster QRKL.
Verification
Let's verify if applying the same pattern to QRKL results in the next term, PSLK.
- First letter: Q (17). Applying -1 shift: \(17 - 1 = 16\). The 16th letter is P.
- Second letter: R (18). Applying +1 shift: \(18 + 1 = 19\). The 19th letter is S.
- Third letter: K (11). Applying +1 shift: \(11 + 1 = 12\). The 12th letter is L.
- Fourth letter: L (12). Applying -1 shift: \(12 - 1 = 11\). The 11th letter is K.
Applying the pattern to QRKL results in PSLK, which is the next term in the given series. This confirms that QRKL is indeed the correct missing term.
Conclusion
The letter cluster that replaces the question mark (?) is QRKL.
| Term | Letters | Positions | Pattern Applied | Next Term |
|---|---|---|---|---|
| 1st | SPIN | 19, 16, 9, 14 | (-1, +1, +1, -1) | RQJM |
| 2nd | RQJM | 18, 17, 10, 13 | QRKL (?) | |
| 3rd | QRKL (?) | 17, 18, 11, 12 | PSLK | |
| 4th | PSLK | 16, 19, 12, 11 | OTMJ |
Revision Table: Letter Series Reasoning
| Concept | Description | Application in this problem |
|---|---|---|
| Identify the Pattern | Look for consistent changes (shifts, skips, sequences) between corresponding letters of consecutive terms. | Found a consistent letter shift pattern (-1, +1, +1, -1). |
| Use Alphabet Positions | Convert letters to their numerical positions (A=1, B=2, ...) to make calculations easier. | Used numerical positions to find the shift: e.g., S(19) to R(18) is -1. |
| Apply the Pattern | Once the pattern is identified, apply it to the term before the question mark to find the missing term. | Applied (-1, +1, +1, -1) to RQJM to get QRKL. |
| Verify the Pattern | Check if applying the pattern to the found term results in the subsequent known term(s). | Applied (-1, +1, +1, -1) to QRKL and confirmed it results in PSLK. |
Additional Information on Letter Series and Reasoning
Letter series questions are common in reasoning sections of competitive exams. They test your ability to identify logical rules and patterns involving letters of the alphabet.
Common types of patterns include:
- Sequential Shift: A fixed number is added or subtracted to the position of each letter to get the corresponding letter in the next term. This is the pattern seen in the current problem.
- Alternating Shift: The shift pattern alternates between terms (e.g., +2 then -3 then +2 then -3).
- Increasing/Decreasing Shift: The shift amount increases or decreases progressively (e.g., +1, +2, +3, ...).
- Reverse Order: The pattern might involve reversing the letters or applying shifts in reverse order within the cluster.
- Skipping Letters: A fixed or patterned number of letters are skipped between terms.
- Combination of Patterns: More complex series might combine multiple rules.
Solving these problems effectively requires familiarity with the alphabet and practice in recognizing different types of patterns. Writing down the letter positions or the changes between them can help visualize the pattern.
Important Questions from Alphabet Series
Select the letter-cluster from among the given options that can replace the question mark (?) in the following series.
KMTC, EVOM, OQXG, IZSQ, ?
Select the set of letters that when sequentially placed in the blanks of the given letter series will complete the series.
k_lmml_mk_mmk_lkkl_mSelect the letter will replace the question mark (?) in the following series.
C, B, B, C, Z, E, W, H, S, ?, NWhich letter will replace the question mark (?) in the following letter series?
E, J, N, Q, S, ?
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
