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)

Question

Prepp Team · Accepted Answer

Finding the Odd Group of Numbers Pattern

This question asks us to identify the group of numbers that is different from the others based on a specific pattern or rule. A crucial instruction is that we must perform operations on the whole numbers as given, without breaking them down into their individual digits.

To find the odd group, we need to analyze each option and see if there's a consistent mathematical relationship between the numbers within the groups.

Analyzing Each Group of Numbers for Patterns

Let's examine the relationship between the consecutive numbers in each group. A common pattern involves differences or ratios between the numbers.

Option 1: (18 – 28 – 48)

Difference between the first and second number: \(28 - 18 = 10\)

Difference between the second and third number: \(48 - 28 = 20\)

Option 2: (17 – 27 – 47)

Difference between the first and second number: \(27 - 17 = 10\)

Difference between the second and third number: \(47 - 27 = 20\)

Option 3: (15 – 25 – 49)

Difference between the first and second number: \(25 - 15 = 10\)

Difference between the second and third number: \(49 - 25 = 24\)

Option 4: (13 – 23 – 43)

Difference between the first and second number: \(23 - 13 = 10\)

Difference between the second and third number: \(43 - 23 = 20\)

Identifying the Consistent Pattern and the Exception

Let's put the differences we calculated into a table to clearly see the pattern.

Group	Difference 1 (Second - First)	Difference 2 (Third - Second)
(18 – 28 – 48)	\(10\)	\(20\)
(17 – 27 – 47)	\(10\)	\(20\)
(15 – 25 – 49)	\(10\)	\(24\)
(13 – 23 – 43)	\(10\)	\(20\)

From the table, it is clear that options 1, 2, and 4 follow a specific pattern where the difference between the first two numbers is \(10\), and the difference between the second and third numbers is \(20\). This can be described as a sequence where each term is obtained by adding \(10\) to the previous term, and then adding \(20\) to the second term to get the third term.

However, option 3 follows a different pattern. While the first difference is still \(10\) (\(25 - 15 = 10\)), the second difference is \(24\) (\(49 - 25 = 24\)). This breaks the pattern observed in the other three groups.

Therefore, the group (15 – 25 – 49) is the odd group of numbers because it does not conform to the \(+10\), \(+20\) difference rule followed by the other options.

Conclusion: The Odd Group of Numbers

The group (15 – 25 – 49) is the odd one out as it does not share the same numerical difference pattern as the other groups.

Revision Table: Finding Odd Group of Numbers

Key steps involved in solving "odd group of numbers" reasoning problems:

Step	Action
1	Understand the rules (e.g., operate on whole numbers).
2	Analyze the relationship between numbers in each option.
3	Look for common patterns (arithmetic, geometric, etc.).
4	Identify the group that deviates from the common pattern.

Additional Information: Numerical Reasoning Questions

Numerical reasoning questions test your ability to work with numbers and identify logical patterns. These questions often appear in aptitude tests for jobs and exams. Common types include number series, finding the odd one out, analogies, and coding/decoding based on numerical relationships.

Practice is key to improving speed and accuracy in recognizing different types of patterns. Pay attention to differences, sums, products, ratios, squares, cubes, prime numbers, and combinations of operations between numbers.