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Question

Which of the following letter-number clusters will replace the question mark (?) in the given series to make it logically complete? 

BLE 6, UEX 11, NXQ 16, GQJ 21, ?

This question was previously asked in
RRB NTPC 2025 Under Graduate CBT 1 Question Paper PDF (20-Jun-2026) (Shift 3)
The correct answer is

ZJC 26

The numbers 6, 11, 16, 21 increase by 5 each time, so the next number is 26.

Tracking the first letters B, U, N, G: each shifts by +19 (mod 26), giving the next letter \(G+19=Z\) (wrapping around).

The second letters L, E, X, Q also shift by +19 (mod 26) consistently, giving the next letter \(Q+19=J\).

The third letters E, X, Q, J shift by the same +19 (mod 26), giving the next letter \(J+19=C\).

Hence, the missing cluster is ZJC 26.

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Similar Questions

  1. Select the alphanumeric-cluster from among the given options that can replace the question mark (?) in the following series.
    k11, m13, q17, s19, ?
  2. Which of the following letter-number clusters will replace the question mark (?) in the given series to make it logically complete?
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Important Questions from Alpha-numeric series

  1. What should come in place of the question mark (?) in the given series based on the English alphabetical order?
    DFA, HJE, LNI, PRM, ?

  2. What should come in place of the question mark (?) in the given series based on the English alphabetical order?
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  3. Which letter-cluster will replace the question mark (?) to complete the given series?
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  4. Select the combination of letters that when sequentially placed in the blanks of the given series will complete the series.
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  5. What should come in place of the question mark (?) in the given series based on the English alphabetical order?

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