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Question

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.

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

254

Finding the Different Number in a Series

This question asks us to identify the number that is different from the rest in a given set of four numbers. This type of problem tests our ability to find a pattern or rule that applies to a group of numbers, and identify the one that doesn't follow that rule. The given numbers are 254, 217, 126, and 189.

Let's examine the properties of these numbers to find a common pattern among three of them.

  • 254
  • 217
  • 126
  • 189

We can try looking for patterns like even/odd, sum of digits, perfect squares or cubes $\pm$ a number, or divisibility rules.

Checking for Divisibility by 7

Let's test if these numbers are divisible by 7.

  • For 217: $217 \div 7$
Calculation Result
$217 \div 7$ 31

217 is divisible by 7 ($217 = 7 \times 31$).

  • For 126: $126 \div 7$
Calculation Result
$126 \div 7$ 18

126 is divisible by 7 ($126 = 7 \times 18$).

  • For 189: $189 \div 7$
Calculation Result
$189 \div 7$ 27

189 is divisible by 7 ($189 = 7 \times 27$).

  • For 254: $254 \div 7$
Calculation Result
$254 \div 7$ $36$ with a remainder ($254 = 7 \times 36 + 2$)

254 is NOT divisible by 7.

Based on this analysis, we can see that three numbers (217, 126, and 189) are divisible by 7, while one number (254) is not divisible by 7. This establishes a clear pattern where 254 is the number that does not fit the rule.

Conclusion

The numbers 217, 126, and 189 share the property of being divisible by 7. The number 254 does not share this property. Therefore, 254 is the number that is different from the rest.

Revision Table: Analyzing Number Properties

Number Divisible by 7? Notes
254 No ($254 = 7 \times 36 + 2$) Not divisible by 7
217 Yes ($217 = 7 \times 31$) Divisible by 7
126 Yes ($126 = 7 \times 18$) Divisible by 7
189 Yes ($189 = 7 \times 27$) Divisible by 7

Additional Information: Odd One Out Reasoning

Odd one out questions in reasoning test involve classifying a group of items (numbers, letters, words, figures) based on a common characteristic or rule. The goal is to identify the one item that does not belong to the group. Common patterns to look for include:

  • Mathematical operations (addition, subtraction, multiplication, division).
  • Properties of numbers (even/odd, prime/composite, perfect squares/cubes, divisibility rules).
  • Sequences or series (arithmetic progression, geometric progression, etc.).
  • Sum or product of digits.
  • Arrangement or structure (for letters, words, or figures).

Finding the pattern often requires checking multiple possibilities until one fits three or more items in the set, leaving only one item that is different.

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Similar Questions

  1. Identify the roll number that doesn't fit this rule.
    Last 3 digits = First 3 digits + 100
  2. If 2 * 3 = 8, 3 * 4 = 81, then 4 * 5 = ?
  3. Find the missing number: 17 : 4914 :: 19 : ?
  4. Find the missing number: $23 : 125 :: 31 : ?$

  5. How many of these roll numbers are palindromes? List: 123321, 654456, 112211, 123456

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

  7. Three of the following four triads are alike in a certain way as they are formed by performing same mathematical operations among themselves and thus form a group. Which triad does NOT belong to that group?

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

    (NOTE: The relation should be found without breaking down the numbers into its constituent digits)

  9. 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.

  10. Three of the following four triads are alike in a certain way as they are formed by performing same mathematical operations among themselves and thus form a group. Which triad does NOT belong to that group?


Important Questions from Number Based

  1. Four number triads have been given, out of which three are alike in some manner and one is different. Select the number triad that is different.

  2. Choose the odd number out of the given options.

  3. Identify the odd one from the following.

  4. Identify the number that is different from the rest.

  5. Four numbers have been given out of which three are alike in some manner, while one is different. Choose the odd one.

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