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Question

Select the number from among the given options that can replace the question mark (?) in the following series.

14, 20, 34, 72, 182, ?

The correct answer is

508

Solving Number Series Patterns

This question asks us to find the next number in the given series: 14, 20, 34, 72, 182, ?

To solve number series questions, we need to identify the pattern or rule that connects consecutive terms. Let's examine the differences between the terms in the series.

Step-by-Step Analysis of the Number Series

First, calculate the difference between each consecutive pair of numbers:

  • Difference between the 2nd and 1st term: $20 - 14 = 6$
  • Difference between the 3rd and 2nd term: $34 - 20 = 14$
  • Difference between the 4th and 3rd term: $72 - 34 = 38$
  • Difference between the 5th and 4th term: $182 - 72 = 110$

So, the series of differences is 6, 14, 38, 110.

Finding the Pattern in the Differences

The differences (6, 14, 38, 110) do not seem to follow a simple arithmetic or geometric progression. Let's look at the differences between these differences (second differences):

  • Difference between the 2nd and 1st difference: $14 - 6 = 8$
  • Difference between the 3rd and 2nd difference: $38 - 14 = 24$
  • Difference between the 4th and 3rd difference: $110 - 38 = 72$

The second differences are 8, 24, 72.

Identifying the Pattern in Second Differences

Let's examine the pattern in the second differences (8, 24, 72):

  • $24 \div 8 = 3$
  • $72 \div 24 = 3$

It appears that each term in the second difference series is obtained by multiplying the previous term by 3.

So, the next term in the second difference series should be $72 \times 3 = 216$.

Determining the Next Terms in the Series

Now we can work backward to find the next number in the original series.

The next difference in the first series of differences (6, 14, 38, 110, ?) will be the last difference (110) plus the next second difference (216).

  • Next difference = $110 + 216 = 326$

The next number in the original series (14, 20, 34, 72, 182, ?) is the last term (182) plus this next difference (326).

  • Next term = $182 + 326 = 508$

Summary of the Pattern

The pattern can be summarized as follows:

Term Number Series Value Difference Second Difference
1 14 - -
2 20 $20 - 14 = 6$ -
3 34 $34 - 20 = 14$ $14 - 6 = 8$
4 72 $72 - 34 = 38$ $38 - 14 = 24$ ($8 \times 3$)
5 182 $182 - 72 = 110$ $110 - 38 = 72$ ($24 \times 3$)
6 ? $110 + 216 = 326$ $72 \times 3 = 216$

The next number in the series is $182 + 326 = 508$.

Identifying the Correct Option for the Number Series

Based on our pattern analysis, the number that replaces the question mark is 508. Let's check the given options:

  1. 380
  2. 580
  3. 308
  4. 508

Our calculated value, 508, matches option 4.

Revision Table: Key Concepts in Number Series

Concept Description Example Pattern
Arithmetic Series Constant difference between terms. 2, 5, 8, 11... (Difference is +3)
Geometric Series Constant ratio between terms. 3, 6, 12, 24... (Ratio is $\times 2$)
Difference Series Pattern found by looking at differences between terms. Can involve one or more levels of differences. 1, 2, 4, 7, 11... (Differences: 1, 2, 3, 4)
Mixed Series Combination of two or more simple patterns. 1, 5, 3, 7, 5, 9... (Alternating +4, -2)

Additional Information on Solving Number Puzzles

Solving number series requires careful observation and often trial and error to find the underlying rule. Here are some tips:

  • Calculate differences between consecutive terms.
  • Calculate differences of differences (second differences) if the first differences don't show a clear pattern.
  • Check for ratios between consecutive terms (geometric series).
  • Look for alternating patterns (e.g., adding and subtracting different numbers, or two interleaved series).
  • Consider patterns involving squares, cubes, prime numbers, or Fibonacci sequence.
  • Sometimes the pattern relates the term number to the term value.
  • Practice with various types of series helps in recognizing patterns more quickly.

In this specific problem, the pattern involved a second-level difference that followed a geometric progression (multiplication by 3).

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Important Questions from Number Series

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

    37, 52, 74, 104, 143, ?

  2. Select the number that can replace the question mark (?) in the following series.

    17, 19, 22, 27, 34, 45, 58,?
  3. Select the number from among the given options that can replace the question mark (?) in the following series.

    10, 14, 31, 35, 73, 77, ?

  4. Select the number from among the given options that can replace the question mark (?) in the following series.

    215, 231, 256, 292, ?

  5. Select the number from among the given options that can replace the question mark (?) in the following series.

    6, 6, 8, 24, 28, 140, ?

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