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Question

Which number will replace the question mark (?) in the following series?

27, 32, 42, 62, ?, 182

The correct answer is

102

Understanding the Number Series Pattern

The question asks us to find the missing number in the given series: 27, 32, 42, 62, ?, 182. To solve this, we need to identify the pattern or rule that governs the sequence of numbers.

Analyzing the Differences Between Terms

Let's look at the differences between consecutive terms in the series:

  • Difference between the 2nd and 1st term: \(32 - 27 = 5\)
  • Difference between the 3rd and 2nd term: \(42 - 32 = 10\)
  • Difference between the 4th and 3rd term: \(62 - 42 = 20\)

We can observe a pattern in these differences: 5, 10, 20. Each difference is double the previous difference.

Identifying the Pattern in Differences

The pattern in the differences is:

  • \(10 = 5 \times 2\)
  • \(20 = 10 \times 2\)

Following this pattern, the next difference should be double the last calculated difference (20).

Next difference = \(20 \times 2 = 40\)

Calculating the Missing Number

The missing number (?) is the 5th term in the series. To find the 5th term, we add the next difference (40) to the 4th term (62).

Missing number = 4th term + next difference

Missing number = \(62 + 40 = 102\)

Verifying the Pattern with the Last Term

Now that we have found the missing number (102), let's check if the pattern continues with the last term (182). The difference between the last term (182) and the number we found (102) should follow the established pattern of differences.

Difference between the 6th and 5th term: \(182 - 102 = 80\)

The previous difference was 40. Is 80 double of 40?

\(40 \times 2 = 80\)

Yes, the pattern holds true. The differences are 5, 10, 20, 40, 80, where each difference is double the previous one.

Conclusion of the Number Series Analysis

The series with the missing number filled in is: 27, 32, 42, 62, 102, 182.

The number that replaces the question mark is 102.

Term Position Term Value Difference from Previous Term
1st 27 -
2nd 32 \(32 - 27 = 5\)
3rd 42 \(42 - 32 = 10\)
4th 62 \(62 - 42 = 20\)
5th (?) 102 \(102 - 62 = 40\)
6th 182 \(182 - 102 = 80\)

Revision Table: Number Series Pattern

This table summarizes the pattern found in the differences between consecutive terms:

Difference Calculation Pattern
First Difference 5 Base difference
Second Difference 10 \(5 \times 2\)
Third Difference 20 \(10 \times 2\)
Fourth Difference 40 \(20 \times 2\)
Fifth Difference 80 \(40 \times 2\)

Additional Information: Solving Number Series Problems

Solving number series problems often involves looking for patterns in the differences or ratios between consecutive terms. Common patterns include:

  • Arithmetic Progression (constant difference)
  • Geometric Progression (constant ratio)
  • Differences forming an Arithmetic or Geometric Progression
  • Alternating patterns
  • Patterns based on squares, cubes, or other mathematical operations
  • Combinations of patterns

It is helpful to calculate the differences between consecutive terms first, and if a clear pattern doesn't emerge there, calculate the differences of the differences (second-order differences), and so on. Checking ratios can also reveal geometric patterns.

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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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