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Question

Select the set that can replace the question marks (?) in the following series.

 $\displaystyle \frac{\text{D}}{23} \; \frac{20}{\text{G}} \; \frac{\text{J}}{17} \; \frac{14}{\text{M}} \; \frac{\text{P}}{11} \; \frac{\text{?}}{\text{?}}$

This question was previously asked in
RRB NTPC 2019 CBT 1 Question Paper (8-Mar-2021) (Shift 2)
The correct answer is
$\frac{8}{\text{S}}$

Analyzing the Series Pattern

The series consists of fractions that alternate between a Letter/Number format and a Number/Letter format. Let's break down the structure:

  • Term 1: $\displaystyle \frac{\text{D}}{23}$ (Letter/Number)
  • Term 2: $\displaystyle \frac{20}{\text{G}}$ (Number/Letter)
  • Term 3: $\displaystyle \frac{\text{J}}{17}$ (Letter/Number)
  • Term 4: $\displaystyle \frac{14}{\text{M}}$ (Number/Letter)
  • Term 5: $\displaystyle \frac{\text{P}}{11}$ (Letter/Number)
  • Term 6: $\displaystyle \frac{\text{?}}{\text{?}}$ (This term should follow the Number/Letter pattern)

Numerator Progression

Let's analyze the sequence of numerators: D, 20, J, 14, P, ?

Convert letters to their corresponding numerical positions in the alphabet (A=1, B=2, ..., Z=26): 4, 20, 10, 14, 16, ?

We observe two interleaved patterns:

  • Numerators at odd positions (1st, 3rd, 5th): D (4), J (10), P (16). This sequence increases by 6 each time (4 + 6 = 10; 10 + 6 = 16).
  • Numerators at even positions (2nd, 4th): 20, 14. This sequence decreases by 6 (20 - 6 = 14).
  • To find the 6th term's numerator (an even position), we continue the second pattern: 14 - 6 = 8.

Therefore, the numerator for the missing term is 8.

Denominator Progression

Now, let's analyze the sequence of denominators: 23, G, 17, M, 11, ?

Convert letters to their numerical positions: 23, 7, 17, 13, 11, ?

We observe two interleaved patterns here as well:

  • Denominators at odd positions (1st, 3rd, 5th): 23, 17, 11. This sequence decreases by 6 each time (23 - 6 = 17; 17 - 6 = 11).
  • Denominators at even positions (2nd, 4th): G (7), M (13). This sequence increases by 6 (7 + 6 = 13).
  • To find the 6th term's denominator (an even position), we continue the second pattern: 13 + 6 = 19.

The 19th letter of the alphabet is S. So, the denominator for the missing term is S.

Determining the Missing Term

Combining the calculated numerator (8) and denominator (S), the missing term in the series is $\displaystyle \frac{8}{\text{S}}$.

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Similar Questions

  1. Which of the following letter-number clusters will replace the question mark (?) in the given series to make it logically complete?
    GBD 14, KFH 17, OJL 20, SNP 23, ?
  2. Which of the following letter-number clusters will replace the question mark (?) in the given series to make it logically complete?
    KFU-15 IIQ-22 GLM-31 EOI-42 ?
  3. Which of the following letter-number clusters will replace the question mark (?) in the given series to make it logically complete?

    HYP 8, LCT 15, PGX 29, TKB 57, XOF 113, ?
  4. Which option will replace the question mark in the below series?
    A25 : Y1 :: L14 : ?
  5. Select the option that can replace the question mark (?) in the given series.

    P3L, N5N, L7P, J11R, H13T, ?
  6. Select the term that can replace the question mark (?) in the following series.

    B3, D10, F17, H24, ?
  7. Select the alphanumeric-cluster that can replace the question mark (?) in the following series.

    B4D, C9I, D16P, ?
  8. Select the alphanumeric-cluster that can replace the question mark (?) in the following series.

    A9B, C49D, E121F, ?
  9. Four letter-pairs have been given, out of which three are alike in some manner and one is different. Select the odd one.
  10. Study the given series carefully and select the option that will come next (in place of the question marks).

    $\frac{\text{C}}{29} \frac{25}{\text{F}} \frac{\text{I}}{21} \frac{17}{\text{L}} \frac{\text{O}}{13} \frac{\text{?}}{\text{?}}$

Important Questions from Letter and Number Based

  1. Select the option in which the numbers are related in the same way as are the numbers of the following set.

    (4, 8, 16)

  2. Select the option that is related to the third number in the same way as the second number is related to the first number.

    23 : 441 : : 28 : ?

  3. Select the option that is related to the third number in the same way as the second number is related to the first number and the sixth number is related to the fifth number.

    12 : 72 ∷ 18 : ? ∷22 : 242
  4. Select the option that is related to the third number in the same way as the second number is related to the first number.

    7 : 56 :: 11 : ?

  5. Select the option in which the numbers are related in the same way as are the numbers of the following set.

    (12, 60, 84)

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