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Question

Study the given series carefully and select the option that will come next (in place of the question marks).

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

This question was previously asked in
RRB NTPC 2019 CBT 1 Question Paper (8-Mar-2021) (Shift 2)
The correct answer is
$\frac{9}{\text{R}}$

Analyzing the Series Pattern

The given series consists of fractions where the components follow distinct patterns for letters, numbers, and their positions.

Series: \frac{C}{29} \frac{25}{F} \frac{I}{21} \frac{17}{L} \frac{O}{13} \frac{?}{?}

We need to identify the pattern for the letters, the numbers, and how they alternate between the numerator and denominator.

Letter Progression Pattern

The letters in the series are C, F, I, L, O. Let's examine their positions in the alphabet:

  • C is the 3rd letter.
  • F is the 6th letter.
  • I is the 9th letter.
  • L is the 12th letter.
  • O is the 15th letter.

There is a consistent increase of 3 positions between consecutive letters.

To find the next letter, we add 3 to the position of O (15):

Next letter position = 15 + 3 = 18.

The 18th letter of the alphabet is R.

Number Progression Pattern

The numbers in the series are 29, 25, 21, 17, 13.

Let's find the difference between consecutive numbers:

  • 29 - 25 = 4
  • 25 - 21 = 4
  • 21 - 17 = 4
  • 17 - 13 = 4

The pattern is a consistent decrease of 4.

To find the next number, we subtract 4 from the last number (13):

Next number = 13 - 4 = 9.

Positional Alternation Rule

Observe the placement of letters and numbers in each fraction:

  • Term 1: Letter in numerator, Number in denominator (\frac{C}{29})
  • Term 2: Number in numerator, Letter in denominator (\frac{25}{F})
  • Term 3: Letter in numerator, Number in denominator (\frac{I}{21})
  • Term 4: Number in numerator, Letter in denominator (\frac{17}{L})
  • Term 5: Letter in numerator, Number in denominator (\frac{O}{13})

The pattern alternates between (Letter/Number) and (Number/Letter).

Since Term 5 is (Letter/Number), Term 6 must follow the (Number/Letter) format.

Final Term Calculation

Combining the results:

  • The next number is 9.
  • The next letter is R.
  • The positional rule dictates Number/Letter.

Therefore, the next term in the series is \frac{9}{R}.

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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 option will replace the question mark in the below series?
    A25 : Y1 :: L14 : ?
  4. Select the set that can replace the question marks (?) in the following series.

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

  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. 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, ?
  10. Select the term that can replace the question mark (?) in the following series.

    U9Y, R14V, O24S, L44P, ?, F164J

Important Questions from Letter and Number Based

  1. Select the related number from the given alternatives that will complete the series:

    Y 2 : 4 : : V 2  : ?
  2. Select the related number from the given alternatives:

    F : 216 : : L : ?
  3. In the following question, select the related number from the given alternatives.

    52 : 57 ∷ 46 : ?
  4. Select the option in which the numbers are related in the same way as are the numbers of the following set.

    (4, 25, 105)

  5. Select the option that is related to the third term in the same way as the second term is related to the first term.

    267 : 5 :: 549 : ?

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