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Question

Select the correct option that will fill in the blank and complete the series.

1, 0, 5, 124, 11, 1330, 17, ________

The correct answer is

4912

Understanding the Number Series Question

The question asks us to identify the pattern in the given number series and use it to find the next term that completes the sequence. The series provided is: 1, 0, 5, 124, 11, 1330, 17, ________.

Analyzing the Given Number Series

Let's list the terms and observe their positions:

  • 1st term: 1
  • 2nd term: 0
  • 3rd term: 5
  • 4th term: 124
  • 5th term: 11
  • 6th term: 1330
  • 7th term: 17
  • 8th term: ? (This is the term we need to find)

We can see that the terms seem to alternate in magnitude, with the even-positioned terms being significantly larger than the preceding odd-positioned terms.

Identifying the Pattern in the Number Series

Let's try to find a relationship between the terms, especially focusing on how an even-positioned term might be related to the odd-positioned term just before it.

  • Consider the 1st term (1) and the 2nd term (0). Can we get 0 from 1? Maybe \(1^3 - 1\)? \(1^3 - 1 = 1 - 1 = 0\). This fits.
  • Consider the 3rd term (5) and the 4th term (124). Can we get 124 from 5? Maybe \(5^3 - 1\)? \(5^3 - 1 = 125 - 1 = 124\). This also fits.
  • Consider the 5th term (11) and the 6th term (1330). Can we get 1330 from 11? Maybe \(11^3 - 1\)? \(11^3 - 1 = 1331 - 1 = 1330\). This fits as well.

It appears there is a consistent pattern connecting the term at an even position to the term at the preceding odd position.

Applying the Pattern to Find the Missing Term

The pattern we have identified is that for any term at an even position \( (2n) \), its value is obtained by cubing the term at the immediately preceding odd position \( (2n-1) \) and then subtracting 1. We can express this as:

\[ \text{Term}(2n) = (\text{Term}(2n-1))^3 - 1 \]

We need to find the 8th term in the series. The 8th position is an even position, where \(2n = 8\), so \(n=4\). The preceding odd position is the 7th term, where \(2n-1 = 7\).

The value of the 7th term is given in the series as 17.

Using the identified pattern, the 8th term will be:

\[ \text{Term}(8) = (\text{Term}(7))^3 - 1 \]

\[ \text{Term}(8) = (17)^3 - 1 \]

Calculating the Value of the Missing Term

Now, let's perform the calculation:

First, we calculate \(17^3\):

\[ 17^3 = 17 \times 17 \times 17 \]

We know that \(17^2 = 289\).

So, \(17^3 = 289 \times 17\).

To calculate \(289 \times 17\), we can multiply:

Calculation StepValue
Multiply 289 by 10\(289 \times 10 = 2890\)
Multiply 289 by 7\(289 \times 7 = 2023\)
Add the results\(2890 + 2023 = 4913\)

So, \(17^3 = 4913\).

Next, we apply the final step of the pattern: subtracting 1.

\[ \text{Term}(8) = 4913 - 1 = 4912 \]

The missing term in the number series is 4912.

Comparing with the Options

Let's check if our calculated value matches any of the provided options:

  • Option 1: 4129
  • Option 2: 4138
  • Option 3: 4912
  • Option 4: 4813

Our result, 4912, matches Option 3.

Conclusion: The Correct Number Series Term

Based on the observed pattern where the term at an even position is the cube of the term at the preceding odd position minus one, the next term in the series 1, 0, 5, 124, 11, 1330, 17, ________ is 4912.

Revision Table: Number Series Pattern Summary

The series alternates between base numbers and results calculated from the preceding base number:

PositionTerm ValuePattern Rule
1st1Base for 2nd term
2nd0\(1^3 - 1\)
3rd5Base for 4th term
4th124\(5^3 - 1\)
5th11Base for 6th term
6th1330\(11^3 - 1\)
7th17Base for 8th term
8th4912\(17^3 - 1\)

Additional Information: Exploring Number Series Patterns

Solving number series questions requires recognizing various types of patterns. Some common pattern types encountered in quantitative aptitude and logical reasoning tests include:

  • Arithmetic Progression: A constant difference is added or subtracted between consecutive terms.
  • Geometric Progression: Terms are multiplied or divided by a constant ratio.
  • Square/Cube Patterns: Terms might be squares or cubes of natural numbers, prime numbers, or the position number, possibly with additions or subtractions.
  • Difference Patterns: The difference between consecutive terms forms its own pattern (e.g., an arithmetic or geometric progression of differences).
  • Alternating Patterns: Two independent series are interwoven within the main series. Our example is a form of alternating pattern where the calculation depends on the term type (odd vs. even position).
  • Fibonacci Sequence: Each term is the sum of the two preceding terms (or variations of this concept).
  • Mixed Patterns: A combination of the above patterns.

To solve number series problems effectively, practice identifying different patterns by examining differences, ratios, or relationships between terms at various positions.

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Important Questions from Alphabet Series

  1. Select the letter-cluster from among the given options that can replace the question mark (?) in the following series.

    KMTC, EVOM, OQXG, IZSQ, ?

  2. 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_m
  3. Select the letter will replace the question mark (?) in the following series.

    C, B, B, C, Z, E, W, H, S, ?, N
  4. Which letter will replace the question mark (?) in the following letter series?

    E, J, N, Q, S, ?

  5. 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

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