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Question

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

4, 34, 58, 76, 88, ?

The correct answer is

94

Analyzing the Number Series Pattern

The given number series is 4, 34, 58, 76, 88, ?. We need to find the number that replaces the question mark by identifying the pattern in the series.

Let's examine the differences between consecutive terms in the series. This method often helps in finding patterns in sequences.

Finding the First Differences in the Series

Subtracting each term from the term that follows it gives us the first differences:

  • Difference between 34 and 4: ${34 - 4 = 30}$
  • Difference between 58 and 34: ${58 - 34 = 24}$
  • Difference between 76 and 58: ${76 - 58 = 18}$
  • Difference between 88 and 76: ${88 - 76 = 12}$

The sequence of first differences is 30, 24, 18, 12.

Finding the Second Differences

Now, let's look at the differences between these first differences:

  • Difference between 24 and 30: ${24 - 30 = -6}$
  • Difference between 18 and 24: ${18 - 24 = -6}$
  • Difference between 12 and 18: ${12 - 18 = -6}$

The second differences are constant, always -6. This indicates a consistent pattern where the difference between terms decreases by 6 each time.

Predicting the Next Term in the Sequence

Since the second difference is a constant -6, the next difference in the first difference sequence (30, 24, 18, 12) will be 6 less than the last difference (12).

  • Next first difference: ${12 - 6 = 6}$

To find the next term in the original series, we add this next first difference (6) to the last term in the original series (88).

  • Next term: ${88 + 6 = 94}$

Therefore, the number that replaces the question mark is 94.

Summary of the Pattern

Term Number Series Term First Difference Second Difference
1 4 - -
2 34 ${34 - 4 = 30}$ -
3 58 ${58 - 34 = 24}$ ${24 - 30 = -6}$
4 76 ${76 - 58 = 18}$ ${18 - 24 = -6}$
5 88 ${88 - 76 = 12}$ ${12 - 18 = -6}$
6 ? ${12 - 6 = 6}$ -6
${88 + 6 = 94}$

The pattern is clear: the differences between consecutive terms decrease by 6 each time. Applying this pattern, the next term is 94.

Revision Table: Number Series Patterns

Understanding common number series patterns is crucial for solving these types of questions. Here are a few types:

  • Arithmetic Series: Constant difference between consecutive terms (first difference is constant).
  • Geometric Series: Constant ratio between consecutive terms.
  • Arithmetic Progression of Higher Order: The differences between consecutive terms form an arithmetic series (like in this question, the second difference is constant).
  • Square/Cube Series: Terms are squares or cubes of natural numbers, sometimes with additions or subtractions.
  • Fibonacci Series: Each term is the sum of the two preceding terms.
  • Mixed Series: Combination of two or more patterns.

Additional Information: How to Solve Number Series Problems

Solving number series problems requires careful observation and systematic checking of different patterns. Here are some steps:

  • Look for Simple Differences: Calculate the differences between consecutive terms. If constant, it's an arithmetic series.
  • Look for Ratios: Calculate the ratio between consecutive terms. If constant, it's a geometric series.
  • Calculate Second/Third Differences: If the first differences show a pattern, calculate the differences of the differences. A constant second or third difference indicates a polynomial sequence.
  • Check for Squares or Cubes: See if terms are related to squares ($1^2, 2^2, 3^2, \dots$) or cubes ($1^3, 2^3, 3^3, \dots$).
  • Check for Alternating Patterns: Sometimes two different patterns alternate within the same series.
  • Look for Combinations: The pattern might be a combination of arithmetic operations (e.g., multiply by 2, then add 1).
  • Consider Fibonacci-like Patterns: Check if a term is the sum or difference of previous terms.
  • Practice: The more series you analyze, the better you become at recognizing patterns quickly.
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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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