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Question

Three of the following four number-pairs are alike in a certain way and one is different. Pick the number-pair that is different from the rest.

This question was previously asked in
SSC CGL 2018 (Tier 2) Statistics Previous Year Paper (22-feb-2018)
The correct answer is

10 : 98

Finding the Different Number Pair

The question asks us to identify the number-pair that is different from the rest among the given four options. We need to look for a pattern or relationship between the two numbers in each pair.

Let's examine each pair and try to find a rule connecting the first number (let's call it \(n\)) to the second number.

Analyzing Each Number Pair

We will test a common pattern often found in such problems: relating the second number to the square of the first number.

  • Pair 1: 7 : 51

    The first number is 7. Let's square it: \(7^2 = 49\). The second number is 51. We can see that \(49 + 2 = 51\). So, the pattern seems to be \(n : n^2 + 2\).

  • Pair 2: 10 : 98

    The first number is 10. Let's square it: \(10^2 = 100\). The second number is 98. We can see that \(100 - 2 = 98\). So, the pattern here seems to be \(n : n^2 - 2\).

  • Pair 3: 8 : 66

    The first number is 8. Let's square it: \(8^2 = 64\). The second number is 66. We can see that \(64 + 2 = 66\). This pair follows the pattern \(n : n^2 + 2\).

  • Pair 4: 13 : 171

    The first number is 13. Let's square it: \(13^2 = 169\). The second number is 171. We can see that \(169 + 2 = 171\). This pair also follows the pattern \(n : n^2 + 2\).

Identifying the Different Pair

Let's summarize the patterns observed for each number-pair:

Number-Pair First Number (\(n\)) Second Number Relationship to \(n^2\) Pattern
7 : 51 7 51 \(7^2 + 2 = 49 + 2 = 51\) \(n : n^2 + 2\)
10 : 98 10 98 \(10^2 - 2 = 100 - 2 = 98\) \(n : n^2 - 2\)
8 : 66 8 66 \(8^2 + 2 = 64 + 2 = 66\) \(n : n^2 + 2\)
13 : 171 13 171 \(13^2 + 2 = 169 + 2 = 171\) \(n : n^2 + 2\)

From the analysis, we can see that three number-pairs (7 : 51, 8 : 66, and 13 : 171) follow the pattern \(n : n^2 + 2\), where \(n\) is the first number and the second number is \(n^2 + 2\). The number-pair 10 : 98 follows a different pattern, which is \(n : n^2 - 2\).

Therefore, the number-pair that is different from the rest is 10 : 98.

Revision Table: Number Pair Patterns

Number Pair Pattern Found Result
7 : 51 \(n^2 + 2\) \(7^2 + 2 = 51\) (Matches)
10 : 98 \(n^2 - 2\) \(10^2 - 2 = 98\) (Matches)
8 : 66 \(n^2 + 2\) \(8^2 + 2 = 66\) (Matches)
13 : 171 \(n^2 + 2\) \(13^2 + 2 = 171\) (Matches)

The pair 10 : 98 is the odd one out because it follows a different rule compared to the other three pairs.

Additional Information: Number Series and Analogy Questions

Number series and number analogy questions, like this one involving number-pairs, are common in logical reasoning tests. They assess your ability to identify patterns and relationships between numbers.

Common patterns include:

  • Arithmetic progression (adding/subtracting a constant)
  • Geometric progression (multiplying/dividing by a constant)
  • Squares or cubes of numbers
  • Combinations of arithmetic/geometric operations with squares/cubes
  • Prime numbers
  • Fibonacci sequence
  • Operations on digits of the number

To solve these questions, it's helpful to try different types of patterns systemically. Squaring or cubing the numbers is often a good starting point when the numbers grow rapidly, as seen in this number-pair problem.

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Similar Questions

  1. Four number-pairs have been given, out of which three are alike in some manner and one is different. Select the number-pair that is different. (Any operation on digits is not allowed)

  2. Select the odd group of numbers. (NOTE: Operations should be performed on the whole numbers, without breaking down the numbers into its constituent digits. E.g.13– Operations on 13 such as adding /subtracting /multiplying etc. to 13 can be performed. Breaking down 13 into 1 and 3 and then performing mathematical operations on 1 and 3 is not allowed)

  3. The second number in the given number pairs is obtained by performing certain mathematical operation(s) on the first number. The same operation(s) are followed in all the number pairs except one. Find that odd number pair.

  4. Select the number-pair in which the two numbers share a different relationship from that shared by the two numbers in the rest of the number-pairs.

  5. Four number-pairs have been given, out of which three are alike in some manner and one is different. Select the number-pair that is different.

  6. Three of the following four number-pairs are alike in a certain way and one is different. Pickthe odd pair out.

  7. Three of the following four numbers are alike in a certain way and one is different. Pick the number that is different from the rest.

  8. Four numbers-pair have been given, out of which three are alike in some manner and is different. Select the number-pair that is different from the rest

  9. Select the option is which the numbers are related in the same way as are the numbers in the given set.

    (45, 24, 441)
  10. Select the option in which the numbers are related in the same ways as are the numbers in the given set.

    (14, 18, 277)

Important Questions from Number Based

  1. In the following question, four number pairs are given. The number on left side of (-) is related to the number of the right side of (-) with some Logic/Rule/Relation. Three are similar on basis of same Logic/Rule/Relation. Select the odd one out from the given alternatives.

  2. Select the set in which the numbers are related in the same way as are the number of the following set.

    (3, 7, 58)

  3. Find the odd number/letters from the given alternatives.

  4. Find the odd number/letters from the given alternatives.

  5. Identify the number which is different from the other.

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