Odd Man Out and Series Quiz

Question 1

Select the odd one out from the following series: 2, 5, 10, 17, 26, 37, 50

Accepted Answer

The series follows the pattern: n² + 1, where n is a natural number.

1² + 1 = 2
2² + 1 = 5
3² + 1 = 10
4² + 1 = 17
5² + 1 = 26
6² + 1 = 37
7² + 1 = 50

However, if we consider the differences between consecutive terms:
5 - 2 = 3
10 - 5 = 5
17 - 10 = 7
26 - 17 = 9
37 - 26 = 11
50 - 37 = 13

The differences are consecutive odd numbers.  10 breaks this pattern as the difference between 5 and 10 is 5, while the difference between 10 and 17 is 7.  Alternatively, 10 is the only number in the series that is not of the form n² + 1 where n is an integer.

Question 2

Find the missing term in the series: 1, 4, 9, 16, 25, __, 49

Accepted Answer

The given series consists of perfect squares of natural numbers.

1 = 1²
4 = 2²
9 = 3²
16 = 4²
25 = 5²
Missing term = 6² = 36
49 = 7²

Therefore, the missing term is 36.

Question 3

Identify the odd one out: 121, 144, 169, 196, 210

Accepted Answer

The numbers 121, 144, 169, and 196 are perfect squares.

121 = 11²
144 = 12²
169 = 13²
196 = 14²

However, 210 is not a perfect square. Its prime factorization is 2 x 3 x 5 x 7. Therefore, 210 is the odd one out.

Question 4

Which one is different from the rest?

Accepted Answer

The question asks to identify the odd one out. Apple, Orange, and Banana are all fruits. Carrot is a root vegetable. Therefore, Carrot is the odd one out.

Let's analyze:
*   Apple - Fruit
*   Orange - Fruit
*   Banana - Fruit
*   Carrot - Vegetable

Question 5

What is the next term in the series: 2, 5, 10, 17, 26, ?

Accepted Answer

Let's analyze the differences between consecutive terms:
*   5 - 2 = 3
*   10 - 5 = 5
*   17 - 10 = 7
*   26 - 17 = 9

The differences are consecutive odd numbers. The next difference should be 11.
Therefore, the next term in the series is 26 + 11 = 37.

The series can be represented as: $a_n = n^2 + 1$, where n starts from 1.
*   $1^2 + 1 = 2$
*   $2^2 + 1 = 5$
*   $3^2 + 1 = 10$
*   $4^2 + 1 = 17$
*   $5^2 + 1 = 26$
*   $6^2 + 1 = 37$

Question 6

Find the odd man out in the following sequence: E3, F4, G5, H6, I7

Accepted Answer

The sequence follows a pattern where the letter increases alphabetically and the number increases by 1. Let's examine each element:
*   E3: E is the 5th letter, and 3 is 5 - 2 = 3
*   F4: F is the 6th letter, and 4 is 6 - 2 = 4
*   G5: G is the 7th letter, and 5 is 7 - 2 = 5
*   H6: H is the 8th letter, and 6 is 8 - 2 = 6
*   I7: I is the 9th letter, and 7 is 9 - 2 = 7

However, the pattern is that the number is the letter's position minus 2.  The correct pattern is that the number is the letter's position + (-1). So, the pattern is letter + 1, number + 1. 
E -> F -> G -> H -> I
3 -> 4 -> 5 -> 6 -> 7
So, H6 is the odd one out because it doesn't follow the pattern of increasing by 1 for both the letter and the number. The correct sequence would be H7.

Question 7

In the following series, find the odd man out:
7, 14, 21, 28, 35, 42, 49, 56, 63, 70
(a) 7
(b) 21
(c) 42
(d) 56

Accepted Answer

The series consists of multiples of 7: 7 * 1, 7 * 2, 7 * 3, 7 * 4, 7 * 5, 7 * 6, 7 * 7, 7 * 8, 7 * 9, 7 * 10.  The odd man out, 7, is the first term and the others are multiples of 7.  The other numbers (14, 21, 28, etc.) follow a consistent arithmetic progression with a common difference of 7.

Question 8

What is the odd number in the following series?
2, 6, 12, 20, 30, 42, 56
(a) 2
(b) 6
(c) 12
(d) 20

Accepted Answer

The series is formed by adding consecutive even numbers to the previous term: 2 + 4 = 6, 6 + 6 = 12, 12 + 8 = 20, 20 + 10 = 30, 30 + 12 = 42, 42 + 14 = 56.  The number 20 is the only term that doesn't follow this pattern of adding consecutive even numbers. The difference between consecutive terms increases by 2 each time: 4, 6, 8, 10, 12, 14.

Question 9

Find the odd number in the following series:
1, 4, 9, 16, 25, 36, 49, 64, 81, 100
(a) 1
(b) 9
(c) 25
(d) 49

Accepted Answer

The series consists of perfect squares: 1², 2², 3², 4², 5², 6², 7², 8², 9², 10². 9 is the only number in the series that is not a perfect square of consecutive integers. All other numbers are perfect squares of integers from 1 to 10.

Question 10

Select the odd one out from the following series: 2, 5, 10, 17, 26, 37, 50

Accepted Answer

The series follows the pattern: n² + 1, where n is a natural number.

1² + 1 = 2
2² + 1 = 5
3² + 1 = 10
4² + 1 = 17
5² + 1 = 26
6² + 1 = 37
7² + 1 = 50

However, if we consider the differences between consecutive terms:
5 - 2 = 3
10 - 5 = 5
17 - 10 = 7
26 - 17 = 9
37 - 26 = 11
50 - 37 = 13

The differences are consecutive odd numbers.  10 breaks this pattern as the difference between 5 and 10 is 5, while the difference between 10 and 17 is 7.  Alternatively, 10 is the only number in the series that is not of the form n² + 1 where n is an integer.

Question 11

Find the missing term in the series: 1, 4, 9, 16, 25, __, 49

Accepted Answer

The given series consists of perfect squares of natural numbers.

1 = 1²
4 = 2²
9 = 3²
16 = 4²
25 = 5²
Missing term = 6² = 36
49 = 7²

Therefore, the missing term is 36.

Question 12

Identify the odd one out: 121, 144, 169, 196, 210

Accepted Answer

The numbers 121, 144, 169, and 196 are perfect squares.

121 = 11²
144 = 12²
169 = 13²
196 = 14²

However, 210 is not a perfect square. Its prime factorization is 2 x 3 x 5 x 7. Therefore, 210 is the odd one out.

Question 13

Select the odd one out from the following series: 2, 5, 10, 17, 26, 37, 50

Accepted Answer

The series follows the pattern: n² + 1, where n is a natural number.

1² + 1 = 2
2² + 1 = 5
3² + 1 = 10
4² + 1 = 17
5² + 1 = 26
6² + 1 = 37
7² + 1 = 50

However, if we consider the differences between consecutive terms:
5 - 2 = 3
10 - 5 = 5
17 - 10 = 7
26 - 17 = 9
37 - 26 = 11
50 - 37 = 13

The differences are consecutive odd numbers.  10 breaks this pattern as the difference between 5 and 10 is 5, while the difference between 10 and 17 is 7.  Alternatively, 10 is the only number in the series that is not of the form n² + 1 where n is an integer.

Question 14

Find the missing term in the series: 1, 4, 9, 16, 25, __, 49

Accepted Answer

The given series consists of perfect squares of natural numbers.

1 = 1²
4 = 2²
9 = 3²
16 = 4²
25 = 5²
Missing term = 6² = 36
49 = 7²

Therefore, the missing term is 36.

Question 15

Identify the odd one out: 121, 144, 169, 196, 210

Accepted Answer

The numbers 121, 144, 169, and 196 are perfect squares.

121 = 11²
144 = 12²
169 = 13²
196 = 14²

However, 210 is not a perfect square. Its prime factorization is 2 x 3 x 5 x 7. Therefore, 210 is the odd one out.

Question 16

Select the odd one out from the following series: 2, 5, 10, 17, 26, 37, 50

Accepted Answer

The series follows the pattern: n² + 1, where n is a natural number.

1² + 1 = 2
2² + 1 = 5
3² + 1 = 10
4² + 1 = 17
5² + 1 = 26
6² + 1 = 37
7² + 1 = 50

However, if we consider the differences between consecutive terms:
5 - 2 = 3
10 - 5 = 5
17 - 10 = 7
26 - 17 = 9
37 - 26 = 11
50 - 37 = 13

The differences are consecutive odd numbers.  10 breaks this pattern as the difference between 5 and 10 is 5, while the difference between 10 and 17 is 7.  Alternatively, 10 is the only number in the series that is not of the form n² + 1 where n is an integer.

Question 17

Find the missing term in the series: 1, 4, 9, 16, 25, __, 49

Accepted Answer

The given series consists of perfect squares of natural numbers.

1 = 1²
4 = 2²
9 = 3²
16 = 4²
25 = 5²
Missing term = 6² = 36
49 = 7²

Therefore, the missing term is 36.

Question 18

Identify the odd one out: 121, 144, 169, 196, 210

Accepted Answer

The numbers 121, 144, 169, and 196 are perfect squares.

121 = 11²
144 = 12²
169 = 13²
196 = 14²

However, 210 is not a perfect square. Its prime factorization is 2 x 3 x 5 x 7. Therefore, 210 is the odd one out.

Question 19

Select the odd one out from the following series: 2, 5, 10, 17, 26, 37, 50

Accepted Answer

The series follows the pattern: n² + 1, where n is a natural number.

1² + 1 = 2
2² + 1 = 5
3² + 1 = 10
4² + 1 = 17
5² + 1 = 26
6² + 1 = 37
7² + 1 = 50

However, if we consider the differences between consecutive terms:
5 - 2 = 3
10 - 5 = 5
17 - 10 = 7
26 - 17 = 9
37 - 26 = 11
50 - 37 = 13

The differences are consecutive odd numbers.  10 breaks this pattern as the difference between 5 and 10 is 5, while the difference between 10 and 17 is 7.  Alternatively, 10 is the only number in the series that is not of the form n² + 1 where n is an integer.

Question 20

Find the missing term in the series: 1, 4, 9, 16, 25, __, 49

Accepted Answer

The given series consists of perfect squares of natural numbers.

1 = 1²
4 = 2²
9 = 3²
16 = 4²
25 = 5²
Missing term = 6² = 36
49 = 7²

Therefore, the missing term is 36.

Question 21

Identify the odd one out: 121, 144, 169, 196, 210

Accepted Answer

The numbers 121, 144, 169, and 196 are perfect squares.

121 = 11²
144 = 12²
169 = 13²
196 = 14²

However, 210 is not a perfect square. Its prime factorization is 2 x 3 x 5 x 7. Therefore, 210 is the odd one out.

Question 22

Select the odd one out from the following series: 2, 5, 10, 17, 26, 37, 50

Accepted Answer

The series follows the pattern: n² + 1, where n is a natural number.

1² + 1 = 2
2² + 1 = 5
3² + 1 = 10
4² + 1 = 17
5² + 1 = 26
6² + 1 = 37
7² + 1 = 50

However, if we consider the differences between consecutive terms:
5 - 2 = 3
10 - 5 = 5
17 - 10 = 7
26 - 17 = 9
37 - 26 = 11
50 - 37 = 13

The differences are consecutive odd numbers.  10 breaks this pattern as the difference between 5 and 10 is 5, while the difference between 10 and 17 is 7.  Alternatively, 10 is the only number in the series that is not of the form n² + 1 where n is an integer.

Question 23

Find the missing term in the series: 1, 4, 9, 16, 25, __, 49

Accepted Answer

The given series consists of perfect squares of natural numbers.

1 = 1²
4 = 2²
9 = 3²
16 = 4²
25 = 5²
Missing term = 6² = 36
49 = 7²

Therefore, the missing term is 36.

Question 24

Identify the odd one out: 121, 144, 169, 196, 210

Accepted Answer

The numbers 121, 144, 169, and 196 are perfect squares.

121 = 11²
144 = 12²
169 = 13²
196 = 14²

However, 210 is not a perfect square. Its prime factorization is 2 x 3 x 5 x 7. Therefore, 210 is the odd one out.

Question 25

In the following series, find the odd man out:
7, 14, 21, 28, 35, 42, 49, 56, 63, 70
(a) 7
(b) 21
(c) 42
(d) 56

Accepted Answer

The series consists of multiples of 7. 14 = 7 * 2, 21 = 7 * 3, 28 = 7 * 4, 35 = 7 * 5, 42 = 7 * 6, 49 = 7 * 7, 56 = 7 * 8, 63 = 7 * 9, 70 = 7 * 10.  7 is not a multiple of 7. Therefore, 7 is the odd man out.

Question 26

What number should come next in the series: 1, 4, 9, 16, 25, ?
(a) 36
(b) 49
(c) 64
(d) 81

Accepted Answer

The series consists of perfect squares: 1², 2², 3², 4², 5², 6². The next number is 6² = 36. However, the question asks for the *next* number in the sequence. The sequence is the squares of consecutive integers. Therefore, the next number is 7² = 49.

Question 27

Identify the odd number in the following sequence: 11, 13, 17, 23, 29, 31
(a) 11
(b) 13
(c) 17
(d) 23

Accepted Answer

The sequence consists of prime numbers. 11, 13, 17, 23, 29, and 31 are all prime numbers. However, 23 is the only composite number in the sequence. A composite number is a positive integer that has at least one divisor other than 1 and itself. 23 is only divisible by 1 and 23. All other numbers are prime.

Question 28

In the following series, find the odd man out:
7, 14, 21, 28, 35, 42, 49, 56, 63, 70

Accepted Answer

The series consists of multiples of 7.  7 * 1 = 7, 7 * 2 = 14, 7 * 3 = 21, 7 * 4 = 28, 7 * 5 = 35, 7 * 6 = 42, 7 * 7 = 49, 7 * 8 = 56, 7 * 9 = 63, 7 * 10 = 70.  49 is the only number in the series that is not a multiple of 7. Therefore, 49 is the odd man out.

Question 29

What number should come next in the series: 1, 4, 9, 16, 25, ?

Accepted Answer

The series consists of perfect squares: 1² = 1, 2² = 4, 3² = 9, 4² = 16, 5² = 25. The next number in the series is 6² = 36. However, the question asks for the *next* number after 25. Therefore, the next number is 7² = 49. The series is the sequence of squares of natural numbers. The next term is 6^2 = 36. The question is slightly ambiguous, but the most logical interpretation is to find the next term in the sequence of squares. The sequence is 1, 4, 9, 16, 25, 36, 49, 64, 81...

Question 30

Find the odd number in the following sequence: 2, 6, 12, 20, 30, 42

Accepted Answer

The sequence is formed by the formula n(n+1) where n starts from 1.  1(1+1) = 2, 2(2+1) = 6, 3(3+1) = 12, 4(4+1) = 20, 5(5+1) = 30, 6(6+1) = 42.  20 is the only number in the sequence that does not follow this pattern. Therefore, 20 is the odd man out.

Question 31

Select the odd one out from the following series: 2, 5, 10, 17, 26, 37, 50

Accepted Answer

The series follows the pattern: n² + 1, where n is a natural number.

1² + 1 = 2
2² + 1 = 5
3² + 1 = 10
4² + 1 = 17
5² + 1 = 26
6² + 1 = 37
7² + 1 = 50

However, if we consider the differences between consecutive terms:
5 - 2 = 3
10 - 5 = 5
17 - 10 = 7
26 - 17 = 9
37 - 26 = 11
50 - 37 = 13

The differences are consecutive odd numbers.  10 breaks this pattern as the difference between 5 and 10 is 5, while the difference between 10 and 17 is 7.  Alternatively, 10 is the only number in the series that is not of the form n² + 1 where n is an integer.

Question 32

Find the missing term in the series: 1, 4, 9, 16, 25, __, 49

Accepted Answer

The given series consists of perfect squares of natural numbers.

1 = 1²
4 = 2²
9 = 3²
16 = 4²
25 = 5²
Missing term = 6² = 36
49 = 7²

Therefore, the missing term is 36.

Question 33

Identify the odd one out: 121, 144, 169, 196, 210

Accepted Answer

The numbers 121, 144, 169, and 196 are perfect squares.

121 = 11²
144 = 12²
169 = 13²
196 = 14²

However, 210 is not a perfect square. Its prime factorization is 2 x 3 x 5 x 7. Therefore, 210 is the odd one out.

Question 34

Select the odd one out from the following series: 2, 5, 10, 17, 26, 37, 50

Accepted Answer

The series follows the pattern: n² + 1, where n is a natural number.

1² + 1 = 2
2² + 1 = 5
3² + 1 = 10
4² + 1 = 17
5² + 1 = 26
6² + 1 = 37
7² + 1 = 50

However, if we consider the differences between consecutive terms:
5 - 2 = 3
10 - 5 = 5
17 - 10 = 7
26 - 17 = 9
37 - 26 = 11
50 - 37 = 13

The differences are consecutive odd numbers.  10 breaks this pattern as the difference between 5 and 10 is 5, while the difference between 10 and 17 is 7.  Alternatively, 10 is the only number in the series that is not of the form n² + 1 where n is an integer.

Question 35

Find the missing term in the series: 1, 4, 9, 16, 25, __, 49

Accepted Answer

The given series consists of perfect squares of natural numbers.

1 = 1²
4 = 2²
9 = 3²
16 = 4²
25 = 5²
Missing term = 6² = 36
49 = 7²

Therefore, the missing term is 36.

Question 36

Identify the odd one out: 121, 144, 169, 196, 210

Accepted Answer

The numbers 121, 144, 169, and 196 are perfect squares.

121 = 11²
144 = 12²
169 = 13²
196 = 14²

210 is not a perfect square. Its prime factorization is 2 x 3 x 5 x 7. Therefore, 210 is the odd one out.

Question 37

In the following series, find the odd man out:
7, 14, 21, 28, 35, 42, 49, 56, 63, 70

Accepted Answer

The series consists of multiples of 7.  7 * 1 = 7, 7 * 2 = 14, 7 * 3 = 21, 7 * 4 = 28, 7 * 5 = 35, 7 * 6 = 42, 7 * 7 = 49, 7 * 8 = 56, 7 * 9 = 63, 7 * 10 = 70.  49 is the only number in the series that is not a multiple of 7. Therefore, 49 is the odd man out.

Question 38

What number should come next in the series: 1, 4, 9, 16, 25, ?

Accepted Answer

The series consists of perfect squares: 1² = 1, 2² = 4, 3² = 9, 4² = 16, 5² = 25. The next number in the series is 6² = 36. However, the question asks for the *next* number after 25. Therefore, the next number is 7² = 49. The series is the sequence of squares of natural numbers. The next term is 6^2 = 36. The question is slightly ambiguous, but the most logical interpretation is to find the next term in the sequence of squares. The series is 1, 4, 9, 16, 25, 36, 49, 64, 81,...

Question 39

Find the odd number in the following sequence: 2, 6, 12, 20, 30, 42

Accepted Answer

The sequence is formed by the formula n(n+1), where n is the position of the number in the sequence. 1(1+1) = 2, 2(2+1) = 6, 3(3+1) = 12, 4(4+1) = 20, 5(5+1) = 30, 6(6+1) = 42.  20 is the only number that does not fit this pattern. The other numbers are the product of consecutive integers.

Question 40

Select the odd one out from the following series: 2, 5, 10, 17, 26, 37, 50

Accepted Answer

The series follows the pattern: n² + 1, where n is a natural number.

1² + 1 = 2
2² + 1 = 5
3² + 1 = 10
4² + 1 = 17
5² + 1 = 26
6² + 1 = 37
7² + 1 = 50

However, if we consider the differences between consecutive terms:
5 - 2 = 3
10 - 5 = 5
17 - 10 = 7
26 - 17 = 9
37 - 26 = 11
50 - 37 = 13

The differences are consecutive odd numbers.  10 breaks this pattern as the difference between 5 and 10 is 5, while the difference between 10 and 17 is 7.  Alternatively, 10 is the only number in the series that is not of the form n² + 1 where n is an integer.

Question 41

Find the missing term in the series: 1, 4, 9, 16, 25, __, 49

Accepted Answer

The given series consists of perfect squares of natural numbers.

1 = 1²
4 = 2²
9 = 3²
16 = 4²
25 = 5²
Missing term = 6² = 36
49 = 7²

Therefore, the missing term is 36.

Question 42

Identify the odd one out: 121, 144, 169, 196, 210

Accepted Answer

The numbers 121, 144, 169, and 196 are perfect squares.

121 = 11²
144 = 12²
169 = 13²
196 = 14²

However, 210 is not a perfect square. Its prime factorization is 2 x 3 x 5 x 7. Therefore, 210 is the odd one out.

Question 43

In the following series, find the odd man out:
7, 14, 21, 28, 35, 42, 49, 56, 63, 70

Accepted Answer

The series consists of multiples of 7.  7 * 1 = 7, 7 * 2 = 14, 7 * 3 = 21, 7 * 4 = 28, 7 * 5 = 35, 7 * 6 = 42, 7 * 7 = 49, 7 * 8 = 56, 7 * 9 = 63, 7 * 10 = 70.  49 is the only number in the series that is not a multiple of 7. Therefore, 49 is the odd man out.

Question 44

What number does the series ‘1, 1, 2, 3, 5, 8, 13, 21, 34’ represent?

Accepted Answer

This is the Fibonacci sequence, where each number is the sum of the two preceding numbers.  1 + 1 = 2, 1 + 2 = 3, 2 + 3 = 5, 3 + 5 = 8, 5 + 8 = 13, 8 + 13 = 21, 13 + 21 = 34, 21 + 34 = 55, 34 + 55 = 89.  The next number in the sequence is 89.

Question 45

In the series: 2, 6, 12, 20, 30, ?

Accepted Answer

The series is formed by adding consecutive even numbers to the previous term.  2 + 4 = 6, 6 + 6 = 12, 12 + 8 = 20, 20 + 10 = 30.  Following this pattern, the next term is 30 + 12 = 42.

Question 46

In the following series, find the odd man out:
7, 14, 21, 28, 35, 42, 56

Accepted Answer

The series consists of multiples of 7: 7 * 1, 7 * 2, 7 * 3, 7 * 4, 7 * 5, 7 * 6, and 7 * 8.  Therefore, 56 is the odd number out as it doesn't follow the pattern of multiples of 7.

Question 47

What is the odd number in the following series?
2, 6, 12, 20, 30, 42, 56

Accepted Answer

The series follows the pattern: n(n+1).  Specifically: 1(2) = 2, 2(3) = 6, 3(4) = 12, 4(5) = 20, 5(6) = 30, 6(7) = 42, 7(8) = 56.  20 is the only term that doesn't fit this pattern.

Question 48

Find the odd number in the following series:
1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121

Accepted Answer

The series consists of perfect squares: 1², 2², 3², 4², 5², 6², 7², 8², 9², 10², 11². 36 (which is 6²) is the only number that is not a perfect square of consecutive integers. All other numbers are perfect squares of consecutive integers starting from 1.

Question 49

In the following series, find the odd man out:
7, 14, 21, 28, 35, 42, 49, 56, 63, 70
(a) 7
(b) 21
(c) 42
(d) 56

Accepted Answer

The series consists of multiples of 7. 14 = 7 * 2, 21 = 7 * 3, 28 = 7 * 4, 35 = 7 * 5, 42 = 7 * 6, 49 = 7 * 7, 56 = 7 * 8, 63 = 7 * 9, 70 = 7 * 10.  7 is not a multiple of 7. Therefore, 7 is the odd man out.

Question 50

What number should come next in the series: 1, 4, 9, 16, 25, ?
(a) 36
(b) 49
(c) 64
(d) 81

Accepted Answer

The series consists of perfect squares: 1², 2², 3², 4², 5², 6². The next number is 6² = 36. However, the question asks for the *next* number in the sequence. The sequence is the squares of consecutive integers. Therefore, the next number is 7² = 49.

Question 51

Identify the odd number in the following sequence: 11, 22, 33, 44, 55, 66, 77, 88, 99, 101
(a) 11
(b) 22
(c) 33
(d) 101

Accepted Answer

The sequence 11, 22, 33, 44, 55, 66, 77, 88, 99 consists of multiples of 11. 101 is not a multiple of 11. It is a prime number. Therefore, 101 is the odd number out.

Question 52

In the following series, find the odd man out:
7, 14, 21, 28, 35, 42, 49, 56, 63, 70
(a) 7
(b) 21
(c) 42
(d) 56

Accepted Answer

The series consists of multiples of 7: 7 * 1, 7 * 2, 7 * 3, 7 * 4, 7 * 5, 7 * 6, 7 * 7, 7 * 8, 7 * 9, 7 * 10.  The odd man out, 7, is the first term and the others are multiples of 7.  The other numbers (14, 21, 28, etc.) follow a consistent arithmetic progression with a common difference of 7.

Question 53

What number should come next in the series: 1, 4, 9, 16, 25, ?
(a) 36
(b) 49
(c) 64
(d) 81

Accepted Answer

The series consists of perfect squares: 1², 2², 3², 4², 5², 6². Therefore, the next number is 6² = 36. However, the question asks for the *next* number after 25, which is 7² = 49. The series is the sequence of squares of natural numbers.

Question 54

Identify the odd number in the following sequence: 11, 22, 33, 44, 55, 66, 77, 88, 99, 100
(a) 11
(b) 22
(c) 33
(d) 100

Accepted Answer

The series consists of multiples of 11: 11 * 1, 11 * 2, 11 * 3, 11 * 4, 11 * 5, 11 * 6, 11 * 7, 11 * 8, 11 * 9, 11 * 10.  100 is not a multiple of 11. It is a composite number and does not fit the pattern of the other numbers in the sequence.

Question 55

In the following series, find the odd man out:
7, 14, 21, 28, 35, 42, 56

Accepted Answer

The series consists of multiples of 7: 7 * 1, 7 * 2, 7 * 3, 7 * 4, 7 * 5, 7 * 6, and 7 * 8.  Therefore, 56 is the odd number out as it doesn't follow the pattern of multiples of 7.

Question 56

What is the odd number out in the following series?
2, 6, 12, 20, 30, 42, 56

Accepted Answer

The series follows the pattern: n(n+1).  Specifically: 1*2 = 2, 2*3 = 6, 3*4 = 12, 4*5 = 20, 5*6 = 30, 6*7 = 42.  20 is the only term that doesn't fit this pattern. The other terms are consecutive products of consecutive integers.

Question 57

Identify the odd number in the following series:
1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121

Accepted Answer

The series consists of perfect squares: 1² = 1, 2² = 4, 3² = 9, 4² = 16, 5² = 25, 6² = 36, 7² = 49, 8² = 64, 9² = 81, 10² = 100, 11² = 121. 36 is the only number in the series that is not a perfect square of an integer.

Question 58

In the following series, find the odd man out:
7, 14, 21, 28, 35, 42, 49, 56, 63, 70

Accepted Answer

The series consists of multiples of 7.  7 * 1 = 7, 7 * 2 = 14, 7 * 3 = 21, 7 * 4 = 28, 7 * 5 = 35, 7 * 6 = 42, 7 * 7 = 49, 7 * 8 = 56, 7 * 9 = 63, 7 * 10 = 70.  49 is the only number in the series that is not a multiple of 7. Therefore, 49 is the odd man out.

Question 59

What number does the series ‘1, 1, 2, 3, 5, 8, 13, 21, 34’ represent?

Accepted Answer

This is the Fibonacci sequence, where each number is the sum of the two preceding numbers.  1 + 1 = 2, 1 + 2 = 3, 2 + 3 = 5, 3 + 5 = 8, 5 + 8 = 13, 8 + 13 = 21, 13 + 21 = 34.  Therefore, the next number in the sequence is 21 + 34 = 55. However, the question asks for the *next* number after that.  Continuing the sequence: 34 + 55 = 89.  So, the next number is 89.

Question 60

In the series: 2, 6, 12, 20, 30, ?

Accepted Answer

The series is formed by adding consecutive even numbers to the previous term.  2 + 4 = 6, 6 + 6 = 12, 12 + 8 = 20, 20 + 10 = 30.  Following this pattern, the next term is 30 + 12 = 42.  Alternatively, the series can be represented as n(n+1) where n = 1, 2, 3, 4, 5.  So, 5(5+1) = 5 * 6 = 30.  The next term would be 6(6+1) = 6 * 7 = 42.

Odd Man Out and Series

Select the odd one out from the following series: 2, 5, 10, 17, 26, 37, 50

Find the missing term in the series: 1, 4, 9, 16, 25, __, 49

Identify the odd one out: 121, 144, 169, 196, 210

Which one is different from the rest?

What is the next term in the series: 2, 5, 10, 17, 26, ?

Find the odd man out in the following sequence: E3, F4, G5, H6, I7

In the following series, find the odd man out: 7, 14, 21, 28, 35, 42, 49, 56, 63, 70 (a) 7 (b) 21 (c) 42 (d) 56

What is the odd number in the following series? 2, 6, 12, 20, 30, 42, 56 (a) 2 (b) 6 (c) 12 (d) 20

Find the odd number in the following series: 1, 4, 9, 16, 25, 36, 49, 64, 81, 100 (a) 1 (b) 9 (c) 25 (d) 49

Select the odd one out from the following series: 2, 5, 10, 17, 26, 37, 50