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.

Question

Prepp Team · Accepted Answer

Understanding the Different Number Problem

This question asks us to find the number that does not fit a certain pattern or rule, unlike the other three numbers provided. We are given four numbers: 56, 12, 30, and 14. Our task is to identify the odd one out by finding a common property among three of them that the fourth number lacks.

Analyzing the Given Numbers

Let's look at the numbers:

56
12
30
14

We need to think about different mathematical properties or relationships these numbers might have. Common things to check include divisibility rules, prime vs. composite, squares or cubes, or relationships between factors.

Discovering the Number Pattern

Let's explore potential patterns for these numbers.

Are they all even? Yes, 56, 12, 30, and 14 are all divisible by 2. So, this is not the differentiating pattern.
Are they related to squares or cubes?
- 56 is close to $7^2 = 49$ or $8^2 = 64$.
- 12 is close to $3^2 = 9$ or $4^2 = 16$.
- 30 is close to $5^2 = 25$ or $6^2 = 36$.
- 14 is close to $3^2 = 9$ or $4^2 = 16$.
This doesn't immediately show a clear pattern for three of the numbers.
Can they be expressed as a product of consecutive integers? Let's check:
- Is 56 a product of consecutive integers? $7 \times 8 = 56$. Yes.
- Is 12 a product of consecutive integers? $3 \times 4 = 12$. Yes.
- Is 30 a product of consecutive integers? $5 \times 6 = 30$. Yes.
- Is 14 a product of consecutive integers? Can we find an integer $n$ such that $n \times (n+1) = 14$?
  - $1 \times 2 = 2$
  - $2 \times 3 = 6$
  - $3 \times 4 = 12$
  - $4 \times 5 = 20$
  The number 14 falls between $3 \times 4 = 12$ and $4 \times 5 = 20$. It cannot be expressed as the product of two consecutive integers.

This pattern seems to work! Three of the numbers (56, 12, and 30) can be written as the product of two consecutive integers, while 14 cannot.

Number	Can be written as $n \times (n+1)$?	Explanation
56	Yes	$7 \times 8 = 56$
12	Yes	$3 \times 4 = 12$
30	Yes	$5 \times 6 = 30$
14	No	Cannot be written as $n \times (n+1)$ for any integer $n$.

Identifying the Different Number

Based on the pattern that three numbers can be expressed as the product of consecutive integers, the number that is different from the rest is the one that cannot be expressed this way.

We found that 56, 12, and 30 follow this pattern ($7 \times 8$, $3 \times 4$, $5 \times 6$), but 14 does not.

Therefore, 14 is the different number.

Revision Table: Summary of Findings

Number	Property	Fits the pattern?
56	Product of consecutive integers $7 \times 8$	Yes
12	Product of consecutive integers $3 \times 4$	Yes
30	Product of consecutive integers $5 \times 6$	Yes
14	Not a product of consecutive integers	No

Additional Information on Number Patterns

Questions like this test your ability to identify underlying logical rules or patterns in a sequence or set of numbers. These patterns can be based on various mathematical properties, such as:

Arithmetic progression (adding or subtracting a constant)
Geometric progression (multiplying or dividing by a constant)
Squares, cubes, or other powers
Prime numbers
Divisibility rules
Sum or product of digits
Relationships between consecutive terms
Figurate numbers (like triangular numbers, which are also products of consecutive numbers divided by 2)

Practicing different types of number series and odd one out questions helps you become familiar with common patterns and improve your logical reasoning skills.