Challenging Number-based Odd One Out Problems for Logical Reasoning Practice

(1)

Group:
2, 4, 6, 9
Which number does not belong and why?


(2)

Group:
5, 10, 15, 20
Which number does not belong and why?


(3)

Group:
3, 9, 27, 30
Which number does not belong and why?


(4)

Group:
8, 16, 24, 32
Which number does not belong and why?


(5)

Group:
1, 4, 9, 15
Which number does not belong and why?


(6)

Group:
11, 13, 17, 20
Which number does not belong and why?


(7)

Group:
4, 16, 64, 128
Which number does not belong and why?


(8)

Group:
7, 14, 21, 25
Which number does not belong and why?


(9)

Group:
12, 18, 24, 30
Which number does not belong and why?


(10)

Group:
5, 25, 125, 150
Which number does not belong and why?


(11)

Group:
10, 20, 30, 35
Which number does not belong and why?


(12)

Group:
3, 6, 9, 12
Which number does not belong and why?


(13)

Group:
15, 25, 35, 40
Which number does not belong and why?


(14)

Group:
2, 3, 4, 5
Which number does not belong and why?


(15)

Group:
5, 10, 15, 40
Which number does not belong and why?


(16)

Group:
9, 12, 18, 24
Which number does not belong and why?


(17)

Group:
7, 14, 21, 32
Which number does not belong and why?


(18)

Group:
1, 8, 27, 40
Which number does not belong and why?


(19)

Group:
6, 12, 18, 21
Which number does not belong and why?


(20)

Group:
2, 3, 6, 12
Which number does not belong and why?


(21)

Group:
9, 16, 20, 25
Which number does not belong and why?


(22)

Group:
5, 7, 11, 13
Which number does not belong and why?


(23)

Group:
16, 24, 36, 50
Which number does not belong and why?


(24)

Group:
100, 200, 400, 700
Which number does not belong and why?


(25)

Group:
11, 22, 33, 44
Which number does not belong and why?

Answer

Answers:


(1)

Group:
2, 4, 6, 9
Answer: 9
Explanation: 2, 4, and 6 are all even numbers, while 9 is odd.


(2)

Group:
5, 10, 15, 20
Answer: 5
Explanation: 10, 15, and 20 are multiples of 5, while 5 is the base number.


(3)

Group:
3, 9, 27, 30
Answer: 30
Explanation: 3, 9, and 27 are powers of 3 (3³, 3², 3¹), while 30 is not.


(4)

Group:
8, 16, 24, 32
Answer: 24
Explanation: 8, 16, and 32 are powers of 2, while 24 is not.


(5)

Group:
1, 4, 9, 15
Answer: 15
Explanation: 1, 4, and 9 are perfect squares (1², 2², 3²), while 15 is not.


(6)

Group:
11, 13, 17, 20
Answer: 20
Explanation: 11, 13, and 17 are prime numbers, while 20 is not.


(7)

Group:
4, 16, 64, 128
Answer: 128
Explanation: 4, 16, and 64 are powers of 4, while 128 is not.


(8)

Group:
7, 14, 21, 25
Answer: 25
Explanation: 7, 14, and 21 are multiples of 7, while 25 is not.


(9)

Group:
12, 18, 24, 30
Answer: 30
Explanation: 12, 18, and 24 are divisible by 6, while 30 is not.


(10)

Group:
5, 25, 125, 150
Answer: 150
Explanation: 5, 25, and 125 are powers of 5, while 150 is not.


(11)

Group:
10, 20, 30, 35
Answer: 35
Explanation: 10, 20, and 30 are divisible by 10, while 35 is not.


(12)

Group:
3, 6, 9, 12
Answer: 12
Explanation: 3, 6, and 9 are multiples of 3, while 12 is a multiple of 4.


(13)

Group:
15, 25, 35, 40
Answer: 40
Explanation: 15, 25, and 35 are multiples of 5, while 40 is a multiple of 10.


(14)

Group:
2, 3, 4, 5
Answer: 4
Explanation: 2, 3, and 5 are prime numbers, while 4 is not.


(15)

Group:
5, 10, 15, 40
Answer: 40
Explanation: 5, 10, and 15 are multiples of 5, while 40 is a multiple of 10.


(16)

Group:
9, 12, 18, 24
Answer: 9
Explanation: 12, 18, and 24 are divisible by 6, while 9 is not.


(17)

Group:
7, 14, 21, 32
Answer: 32
Explanation: 7, 14, and 21 are multiples of 7, while 32 is not.


(18)

Group:
1, 8, 27, 40
Answer: 40
Explanation: 1, 8, and 27 are cubes (1³, 2³, 3³), while 40 is not.


(19)

Group:
6, 12, 18, 21
Answer: 21
Explanation: 6, 12, and 18 are divisible by 6, while 21 is divisible by 7.


(20)

Group:
2, 3, 6, 12
Answer: 12
Explanation: 2, 3, and 6 are factors of 6, while 12 is not.


(21)

Group:
9, 16, 20, 25
Answer: 20
Explanation: 9, 16, and 25 are perfect squares, while 20 is not.


(22)

Group:
5, 7, 11, 13
Answer: 7
Explanation: 5, 11, and 13 are primes, while 7 is the only number that appears more than once in the sequence.


(23)

Group:
16, 24, 36, 50
Answer: 50
Explanation: 16, 24, and 36 are perfect squares or even multiples, while 50 is not.


(24)

Group:
100, 200, 400, 700
Answer: 700
Explanation: 100, 200, and 400 are powers of 2 (in terms of factors), while 700 is not.


(25)

Group:
11, 22, 33, 44
Answer: 33
Explanation: 11, 22, and 44 are multiples of 11, while 33 is not.