138 Reasoning question on Number Series

Here are some reasoning questions on number series for you to solve:

Example 1:

Question:
What is the next number in the series?
2, 5, 10, 17, 26, ___?

Solution:
The difference between consecutive terms is increasing by 2:

5 – 2 = 3
10 – 5 = 5
17 – 10 = 7
26 – 17 = 9

So, the next difference should be 11.
Thus, the next number in the series is:
26 + 11 = 37

Example 2:

Question:
What is the next number in the series?
3, 6, 12, 24, 48, ___?

Solution:
The series is doubling each time:

3 × 2 = 6
6 × 2 = 12
12 × 2 = 24
24 × 2 = 48

So, the next number is:
48 × 2 = 96

Example 3:

Question:
What is the next number in the series?
1, 4, 9, 16, 25, ___?

Solution:
The numbers are perfect squares:

1 = 1²
4 = 2²
9 = 3²
16 = 4²
25 = 5²

So, the next number will be:
6² = 36

Example 4:

Question:
What is the next number in the series?
1, 1, 2, 3, 5, 8, ___?

Solution:
This is the Fibonacci series, where each number is the sum of the two preceding ones:

1 + 1 = 2
1 + 2 = 3
2 + 3 = 5
3 + 5 = 8

So, the next number will be:
5 + 8 = 13

Example 5:

Question:
What is the next number in the series?
0, 1, 3, 6, 10, ___?

Solution:
The differences between consecutive numbers are increasing by 1:

1 – 0 = 1
3 – 1 = 2
6 – 3 = 3
10 – 6 = 4

The next difference will be 5.
So, the next number will be:
10 + 5 = 15

Example 6:

Question:
What is the next number in the series?
1, 3, 6, 10, 15, ___?

Solution:
The differences between consecutive numbers are increasing by 1:

3 – 1 = 2
6 – 3 = 3
10 – 6 = 4
15 – 10 = 5

The next difference will be 6.
So, the next number will be:
15 + 6 = 21

Example 7:

Question:
What is the next number in the series?
1, 4, 9, 16, 25, ___?

Solution:
These are consecutive perfect squares:

1 = 1²
4 = 2²
9 = 3²
16 = 4²
25 = 5²

So, the next number will be:
6² = 36

Example 8:

Question:
What is the next number in the series?
2, 6, 12, 20, 30, ___?

Solution:
The differences between consecutive numbers are increasing by 2:

6 – 2 = 4
12 – 6 = 6
20 – 12 = 8
30 – 20 = 10

The next difference will be 12.
So, the next number will be:
30 + 12 = 42

Example 9:

Question:
What is the next number in the series?
1, 8, 27, 64, ___?

Solution:
These are cubes of consecutive natural numbers:

1 = 1³
8 = 2³
27 = 3³
64 = 4³

So, the next number will be:
5³ = 125

Example 10:

Question:
What is the next number in the series?
1, 2, 6, 24, 120, ___?

Solution:
These are the factorials of consecutive numbers:

1 = 1!
2 = 2!
6 = 3!
24 = 4!
120 = 5!

So, the next number will be:
6! = 720

Example 11:

Question:
What is the next number in the series?
2, 10, 30, 68, 130, ___?

Solution:
The differences between consecutive numbers are increasing by 8:

10 – 2 = 8
30 – 10 = 20
68 – 30 = 38
130 – 68 = 62

The next difference will be 92.
So, the next number will be:
130 + 92 = 222

Example 12:

Question:
What is the next number in the series?
3, 6, 12, 24, 48, ___?

Solution:
The series is doubling each time:

3 × 2 = 6
6 × 2 = 12
12 × 2 = 24
24 × 2 = 48

So, the next number will be:
48 × 2 = 96

Example 13:

Question:
What is the next number in the series?
5, 10, 20, 40, 80, ___?

Solution:
The series is doubling each time:

5 × 2 = 10
10 × 2 = 20
20 × 2 = 40
40 × 2 = 80

So, the next number will be:
80 × 2 = 160

Example 14:

Question:
What is the next number in the series?
2, 4, 8, 16, 32, ___?

Solution:
The series is doubling each time:

2 × 2 = 4
4 × 2 = 8
8 × 2 = 16
16 × 2 = 32

So, the next number will be:
32 × 2 = 64

Example 15:

Question:
What is the next number in the series?
3, 6, 11, 18, 27, ___?

Solution:
The differences between consecutive numbers are increasing by 2:

6 – 3 = 3
11 – 6 = 5
18 – 11 = 7
27 – 18 = 9

The next difference will be 11.
So, the next number will be:
27 + 11 = 38

Example 16:

Question:
What is the next number in the series?
1, 1, 2, 6, 24, ___?

Solution:
The series is the factorial of consecutive numbers:

1 = 1!
1 = 1!
2 = 2!
6 = 3!
24 = 4!

So, the next number will be:
5! = 120

Example 17:

Question:
What is the next number in the series?
4, 9, 16, 25, 36, ___?

Solution:
These are consecutive perfect squares:

4 = 2²
9 = 3²
16 = 4²
25 = 5²
36 = 6²

So, the next number will be:
7² = 49

Example 18:

Question:
What is the next number in the series?
1, 2, 6, 24, 120, ___?

Solution:
The series is the factorial of consecutive numbers:

1 = 1!
2 = 2!
6 = 3!
24 = 4!
120 = 5!

So, the next number will be:
6! = 720

Example 19:

Question:
What is the next number in the series?
7, 14, 28, 56, 112, ___?

Solution:
The series is doubling each time:

7 × 2 = 14
14 × 2 = 28
28 × 2 = 56
56 × 2 = 112

So, the next number will be:
112 × 2 = 224

Example 20:

Question:
What is the next number in the series?
100, 98, 94, 88, 80, ___?

Solution:
The differences between consecutive numbers are decreasing by 2 each time:

98 – 100 = -2
94 – 98 = -4
88 – 94 = -6
80 – 88 = -8

The next difference will be -10.
So, the next number will be:
80 – 10 = 70

Example 21:

Question:
What is the next number in the series?
2, 4, 8, 16, 32, ___?

Solution:
The series is doubling each time:

2 × 2 = 4
4 × 2 = 8
8 × 2 = 16
16 × 2 = 32

So, the next number will be:
32 × 2 = 64

Example 22:

Question:
What is the next number in the series?
1, 3, 6, 10, 15, ___?

Solution:
The differences between consecutive numbers are increasing by 1:

3 – 1 = 2
6 – 3 = 3
10 – 6 = 4
15 – 10 = 5

The next difference will be 6.
So, the next number will be:
15 + 6 = 21

Example 23:

Question:
What is the next number in the series?
2, 3, 5, 7, 11, ___?

Solution:
These are prime numbers in order:

2, 3, 5, 7, 11, …

The next prime number after 11 is 13.

Example 24:

Question:
What is the next number in the series?
0, 1, 4, 9, 16, ___?

Solution:
These are consecutive perfect squares:

0 = 0²
1 = 1²
4 = 2²
9 = 3²
16 = 4²

So, the next number will be:
5² = 25

Example 25:

Question:
What is the next number in the series?
1, 2, 6, 24, 120, ___?

Solution:
The series follows the pattern of factorials:

1 = 1!
2 = 2!
6 = 3!
24 = 4!
120 = 5!

So, the next number will be:
6! = 720

Example 26:

Question:
What is the next number in the series?
1, 3, 7, 15, 31, ___?

Solution:
The series is increasing by consecutive powers of 2:

1 + 2 = 3
3 + 4 = 7
7 + 8 = 15
15 + 16 = 31

So, the next number will be:
31 + 32 = 63

Example 27:

Question:
What is the next number in the series?
3, 9, 27, 81, 243, ___?

Solution:
The series is multiplying each number by 3:

3 × 3 = 9
9 × 3 = 27
27 × 3 = 81
81 × 3 = 243

So, the next number will be:
243 × 3 = 729

Example 28:

Question:
What is the next number in the series?
1, 1, 3, 15, 93, ___?

Solution:
The pattern in this series is multiplying the number by an increasing integer:

1 × 1 = 1
1 × 2 = 3
3 × 5 = 15
15 × 7 = 93

The next multiplication is by 9:
93 × 9 = 837

Example 29:

Question:
What is the next number in the series?
2, 6, 12, 20, 30, ___?

Solution:
The differences between consecutive numbers are increasing by 2:

6 – 2 = 4
12 – 6 = 6
20 – 12 = 8
30 – 20 = 10

The next difference will be 12.
So, the next number will be:
30 + 12 = 42

Example 30:

Question:
What is the next number in the series?
1, 4, 7, 10, 13, ___?

Solution:
The difference between each consecutive number is 3:

4 – 1 = 3
7 – 4 = 3
10 – 7 = 3
13 – 10 = 3

So, the next number will be:
13 + 3 = 16

Example 31:

Question:
What is the next number in the series?
1, 5, 13, 25, 41, ___?

Solution:
The differences between consecutive numbers are increasing by 4:

5 – 1 = 4
13 – 5 = 8
25 – 13 = 12
41 – 25 = 16

The next difference will be 20.
So, the next number will be:
41 + 20 = 61

Example 32:

Question:
What is the next number in the series?
3, 6, 12, 24, 48, ___?

Solution:
The series is doubling each time:

3 × 2 = 6
6 × 2 = 12
12 × 2 = 24
24 × 2 = 48

So, the next number will be:
48 × 2 = 96

Example 33:

Question:
What is the next number in the series?
5, 10, 20, 40, 80, ___?

Solution:
The series is doubling each time:

5 × 2 = 10
10 × 2 = 20
20 × 2 = 40
40 × 2 = 80

So, the next number will be:
80 × 2 = 160

Example 34:

Question:
What is the next number in the series?
1, 4, 9, 16, 25, ___?

Solution:
These are perfect squares of consecutive numbers:

1 = 1²
4 = 2²
9 = 3²
16 = 4²
25 = 5²

So, the next number will be:
6² = 36

Example 35:

Question:
What is the next number in the series?
1, 2, 6, 24, 120, ___?

Solution:
The series is the factorial of consecutive numbers:

1 = 1!
2 = 2!
6 = 3!
24 = 4!
120 = 5!

So, the next number will be:
6! = 720

Example 36:

Question:
What is the next number in the series?
1, 1, 2, 6, 24, ___?

Solution:
The series follows the pattern of factorials:

1 = 1!
1 = 1!
2 = 2!
6 = 3!
24 = 4!

So, the next number will be:
5! = 120

Example 37:

Question:
What is the next number in the series?
10, 20, 40, 80, 160, ___?

Solution:
The series is doubling each time:

10 × 2 = 20
20 × 2 = 40
40 × 2 = 80
80 × 2 = 160

So, the next number will be:
160 × 2 = 320

Example 38:

Question:
What is the next number in the series?
4, 8, 16, 32, 64, ___?

Solution:
The series is doubling each time:

4 × 2 = 8
8 × 2 = 16
16 × 2 = 32
32 × 2 = 64

So, the next number will be:
64 × 2 = 128

Example 39:

Question:
What is the next number in the series?
5, 12, 21, 32, 45, ___?

Solution:
The differences between consecutive numbers are increasing by 2 each time:

12 – 5 = 7
21 – 12 = 9
32 – 21 = 11
45 – 32 = 13

The next difference will be 15.
So, the next number will be:
45 + 15 = 60

Example 40:

Question:
What is the next number in the series?
2, 5, 10, 17, 26, ___?

Solution:
The differences between consecutive numbers are increasing by 2:

5 – 2 = 3
10 – 5 = 5
17 – 10 = 7
26 – 17 = 9

The next difference will be 11.
So, the next number will be:
26 + 11 = 37

Example 41:

Question:
What is the next number in the series?
4, 9, 16, 25, 36, ___?

Solution:
These are consecutive perfect squares:

4 = 2²
9 = 3²
16 = 4²
25 = 5²
36 = 6²

So, the next number will be:
7² = 49

Example 42:

Question:
What is the next number in the series?
1, 2, 6, 24, 120, ___?

Solution:
This series follows the pattern of factorials:

1 = 1!
2 = 2!
6 = 3!
24 = 4!
120 = 5!

So, the next number will be:
6! = 720

Example 43:

Question:
What is the next number in the series?
2, 5, 10, 17, 26, ___?

Solution:
The differences between consecutive terms are increasing by 2:

5 – 2 = 3
10 – 5 = 5
17 – 10 = 7
26 – 17 = 9

The next difference will be 11.
So, the next number will be:
26 + 11 = 37

Example 44:

Question:
What is the next number in the series?
3, 6, 12, 24, 48, ___?

Solution:
The series is doubling each time:

3 × 2 = 6
6 × 2 = 12
12 × 2 = 24
24 × 2 = 48

So, the next number will be:
48 × 2 = 96

Example 45:

Question:
What is the next number in the series?
5, 12, 21, 32, 45, ___?

Solution:
The differences between consecutive numbers are increasing by 2 each time:

12 – 5 = 7
21 – 12 = 9
32 – 21 = 11
45 – 32 = 13

The next difference will be 15.
So, the next number will be:
45 + 15 = 60

Example 46:

Question:
What is the next number in the series?
1, 2, 3, 5, 8, ___?

Solution:
This is a Fibonacci series, where each number is the sum of the previous two:

1 + 2 = 3
2 + 3 = 5
3 + 5 = 8

So, the next number will be:
5 + 8 = 13

Example 47:

Question:
What is the next number in the series?
100, 200, 400, 800, 1600, ___?

Solution:
The series is doubling each time:

100 × 2 = 200
200 × 2 = 400
400 × 2 = 800
800 × 2 = 1600

So, the next number will be:
1600 × 2 = 3200

Example 48:

Question:
What is the next number in the series?
10, 20, 40, 80, 160, ___?

Solution:
The series is doubling each time:

10 × 2 = 20
20 × 2 = 40
40 × 2 = 80
80 × 2 = 160

So, the next number will be:
160 × 2 = 320

Example 49:

Question:
What is the next number in the series?
2, 4, 8, 16, 32, ___?

Solution:
The series is doubling each time:

2 × 2 = 4
4 × 2 = 8
8 × 2 = 16
16 × 2 = 32

So, the next number will be:
32 × 2 = 64

Example 50:

Question:
What is the next number in the series?
3, 9, 27, 81, 243, ___?

Solution:
The series is multiplying by 3 each time:

3 × 3 = 9
9 × 3 = 27
27 × 3 = 81
81 × 3 = 243

So, the next number will be:
243 × 3 = 729

Example 51:

Question:
What is the next number in the series?
1, 4, 9, 16, 25, ___?

Solution:
These are perfect squares of consecutive numbers:

1 = 1²
4 = 2²
9 = 3²
16 = 4²
25 = 5²

So, the next number will be:
6² = 36

Example 52:

Question:
What is the next number in the series?
3, 12, 27, 48, 75, ___?

Solution:
The differences between consecutive numbers are increasing by 6 each time:

12 – 3 = 9
27 – 12 = 15
48 – 27 = 21
75 – 48 = 27

The next difference will be 33.
So, the next number will be:
75 + 33 = 108

Example 53:

Question:
What is the next number in the series?
5, 15, 45, 135, 405, ___?

Solution:
The series is multiplying by 3 each time:

5 × 3 = 15
15 × 3 = 45
45 × 3 = 135
135 × 3 = 405

So, the next number will be:
405 × 3 = 1215

Example 54:

Question:
What is the next number in the series?
2, 6, 12, 20, 30, ___?

Solution:
The differences between consecutive numbers are increasing by 2:

6 – 2 = 4
12 – 6 = 6
20 – 12 = 8
30 – 20 = 10

The next difference will be 12.
So, the next number will be:
30 + 12 = 42

Example 55:

Question:
What is the next number in the series?
1, 1, 2, 6, 24, ___?

Solution:
The series follows the pattern of factorials:

1 = 1!
1 = 1!
2 = 2!
6 = 3!
24 = 4!

So, the next number will be:
5! = 120

Example 56:

Question:
What is the next number in the series?
1, 3, 6, 10, 15, ___?

Solution:
The differences between consecutive terms are increasing by 1:

3 – 1 = 2
6 – 3 = 3
10 – 6 = 4
15 – 10 = 5

The next difference will be 6.
So, the next number will be:
15 + 6 = 21

Example 57:

Question:
What is the next number in the series?
2, 3, 5, 8, 12, ___?

Solution:
The differences between consecutive numbers are increasing by 1:

3 – 2 = 1
5 – 3 = 2
8 – 5 = 3
12 – 8 = 4

The next difference will be 5.
So, the next number will be:
12 + 5 = 17

Example 58:

Question:
What is the next number in the series?
5, 7, 11, 17, 23, ___?

Solution:
The numbers in the series are consecutive prime numbers:

So, the next prime number after 23 is:
29

Example 59:

Question:
What is the next number in the series?
1, 3, 7, 13, 21, ___?

Solution:
The differences between consecutive terms are increasing by 2 each time:

3 – 1 = 2
7 – 3 = 4
13 – 7 = 6
21 – 13 = 8

The next difference will be 10.
So, the next number will be:
21 + 10 = 31

Example 60:

Question:
What is the next number in the series?
8, 16, 32, 64, 128, ___?

Solution:
The series is doubling each time:

8 × 2 = 16
16 × 2 = 32
32 × 2 = 64
64 × 2 = 128

So, the next number will be:
128 × 2 = 256

Example 61:

Question:
What is the next number in the series?
3, 6, 12, 24, 48, ___?

Solution:
The series is doubling each time:

3 × 2 = 6
6 × 2 = 12
12 × 2 = 24
24 × 2 = 48

So, the next number will be:
48 × 2 = 96

Example 62:

Question:
What is the next number in the series?
10, 50, 250, 1250, ___?

Solution:
The series is multiplying by 5 each time:

10 × 5 = 50
50 × 5 = 250
250 × 5 = 1250

So, the next number will be:
1250 × 5 = 6250

Example 63:

Question:
What is the next number in the series?
6, 11, 16, 21, 26, ___?

Solution:
The difference between each consecutive number is 5:

11 – 6 = 5
16 – 11 = 5
21 – 16 = 5
26 – 21 = 5

So, the next number will be:
26 + 5 = 31

Example 64:

Question:
What is the next number in the series?
1, 1, 2, 6, 24, ___?

Solution:
This is a factorial sequence:

1 = 1!
1 = 1!
2 = 2!
6 = 3!
24 = 4!

The next number is:
5! = 120

Example 65:

Question:
What is the next number in the series?
0, 1, 3, 6, 10, ___?

Solution:
The differences between consecutive numbers are increasing by 1:

1 – 0 = 1
3 – 1 = 2
6 – 3 = 3
10 – 6 = 4

The next difference will be 5.
So, the next number will be:
10 + 5 = 15

Also Read :- Reasoning question on puzzles

Example 66:

Question:
What is the next number in the series?
2, 4, 8, 16, 32, ___?

Solution:
The series is doubling each time:

2 × 2 = 4
4 × 2 = 8
8 × 2 = 16
16 × 2 = 32

So, the next number will be:
32 × 2 = 64

Example 67:

Question:
What is the next number in the series?
5, 14, 29, 50, 77, ___?

Solution:
The differences between consecutive numbers are increasing by 9 each time:

14 – 5 = 9
29 – 14 = 15
50 – 29 = 21
77 – 50 = 27

The next difference will be 33.
So, the next number will be:
77 + 33 = 110

Example 68:

Question:
What is the next number in the series?
11, 22, 33, 44, 55, ___?

Solution:
The numbers are increasing by 11 each time:

22 – 11 = 11
33 – 22 = 11
44 – 33 = 11
55 – 44 = 11

So, the next number will be:
55 + 11 = 66

Example 69:

Question:
What is the next number in the series?
3, 9, 18, 36, 72, ___?

Solution:
The series is doubling and then multiplying by 1.5 each time:

3 × 3 = 9
9 × 2 = 18
18 × 2 = 36
36 × 2 = 72

So, the next number will be:
72 × 2 = 144

Example 70:

Question:
What is the next number in the series?
5, 10, 20, 40, 80, ___?

Solution:
The series is doubling each time:

5 × 2 = 10
10 × 2 = 20
20 × 2 = 40
40 × 2 = 80

So, the next number will be:
80 × 2 = 160

Example 71:

Question:
What is the next number in the series?
2, 5, 10, 17, 26, ___?

Solution:
The differences between consecutive terms are increasing by 2 each time:

5 – 2 = 3
10 – 5 = 5
17 – 10 = 7
26 – 17 = 9

The next difference will be 11.
So, the next number will be:
26 + 11 = 37

Example 72:

Question:
What is the next number in the series?
1, 4, 9, 16, 25, ___?

Solution:
These are consecutive perfect squares:

1 = 1²
4 = 2²
9 = 3²
16 = 4²
25 = 5²

The next number will be:
6² = 36

Example 73:

Question:
What is the next number in the series?
10, 20, 30, 40, 50, ___?

Solution:
The series increases by 10 each time:

20 – 10 = 10
30 – 20 = 10
40 – 30 = 10
50 – 40 = 10

So, the next number will be:
50 + 10 = 60

Example 74:

Question:
What is the next number in the series?
1, 1, 2, 6, 24, ___?

Solution:
This series follows the factorial pattern:

1 = 1!
1 = 1!
2 = 2!
6 = 3!
24 = 4!

So, the next number will be:
5! = 120

Example 75:

Question:
What is the next number in the series?
6, 11, 16, 21, 26, ___?

Solution:
The differences between consecutive numbers are constant (5):

11 – 6 = 5
16 – 11 = 5
21 – 16 = 5
26 – 21 = 5

So, the next number will be:
26 + 5 = 31

Example 76:

Question:
What is the next number in the series?
3, 6, 12, 24, 48, ___?

Solution:
The series is doubling each time:

3 × 2 = 6
6 × 2 = 12
12 × 2 = 24
24 × 2 = 48

So, the next number will be:
48 × 2 = 96

Example 77:

Question:
What is the next number in the series?
2, 4, 8, 16, 32, ___?

Solution:
The series is doubling each time:

2 × 2 = 4
4 × 2 = 8
8 × 2 = 16
16 × 2 = 32

So, the next number will be:
32 × 2 = 64

Example 78:

Question:
What is the next number in the series?
5, 12, 21, 32, 45, ___?

Solution:
The differences between consecutive terms are increasing by 2 each time:

12 – 5 = 7
21 – 12 = 9
32 – 21 = 11
45 – 32 = 13

The next difference will be 15.
So, the next number will be:
45 + 15 = 60

Example 79:

Question:
What is the next number in the series?
2, 5, 10, 17, 26, ___?

Solution:
The differences between consecutive terms are increasing by 2:

5 – 2 = 3
10 – 5 = 5
17 – 10 = 7
26 – 17 = 9

The next difference will be 11.
So, the next number will be:
26 + 11 = 37

Example 80:

Question:
What is the next number in the series?
3, 6, 9, 12, 15, ___?

Solution:
The series is increasing by 3 each time:

6 – 3 = 3
9 – 6 = 3
12 – 9 = 3
15 – 12 = 3

So, the next number will be:
15 + 3 = 18

Example 81:

Question:
What is the next number in the series?
10, 30, 60, 100, 150, ___?

Solution:
The differences between consecutive terms are increasing by 20 each time:

30 – 10 = 20
60 – 30 = 30
100 – 60 = 40
150 – 100 = 50

The next difference will be 60.
So, the next number will be:
150 + 60 = 210

Example 82:

Question:
What is the next number in the series?
1, 2, 6, 24, 120, ___?

Solution:
This series is the sequence of factorials:

1 = 1!
2 = 2!
6 = 3!
24 = 4!
120 = 5!

So, the next number will be:
6! = 720

Example 83:

Question:
What is the next number in the series?
3, 9, 27, 81, 243, ___?

Solution:
The series is multiplying by 3 each time:

3 × 3 = 9
9 × 3 = 27
27 × 3 = 81
81 × 3 = 243

So, the next number will be:
243 × 3 = 729

Example 84:

Question:
What is the next number in the series?
2, 3, 5, 7, 11, ___?

Solution:
The series is consisting of consecutive prime numbers:

The next prime number is:
13

Example 85:

Question:
What is the next number in the series?
1, 3, 9, 27, 81, ___?

Solution:
The series is multiplying by 3 each time:

1 × 3 = 3
3 × 3 = 9
9 × 3 = 27
27 × 3 = 81

So, the next number will be:
81 × 3 = 243

Example 86:

Question:
What is the next number in the series?
1, 2, 4, 8, 16, ___?

Solution:
The series is doubling each time:

1 × 2 = 2
2 × 2 = 4
4 × 2 = 8
8 × 2 = 16

So, the next number will be:
16 × 2 = 32

Example 87:

Question:
What is the next number in the series?
5, 15, 45, 135, 405, ___?

Solution:
The series is multiplying by 3 each time:

5 × 3 = 15
15 × 3 = 45
45 × 3 = 135
135 × 3 = 405

So, the next number will be:
405 × 3 = 1215

Example 88:

Question:
What is the next number in the series?
1, 8, 27, 64, 125, ___?

Solution:
The series consists of cubes of consecutive integers:

1 = 1³
8 = 2³
27 = 3³
64 = 4³
125 = 5³

The next number will be:
6³ = 216

Example 89:

Question:
What is the next number in the series?
4, 8, 16, 32, 64, ___?

Solution:
The series is doubling each time:

4 × 2 = 8
8 × 2 = 16
16 × 2 = 32
32 × 2 = 64

So, the next number will be:
64 × 2 = 128

Example 90:

Question:
What is the next number in the series?
5, 11, 17, 23, 29, ___?

Solution:
The series consists of consecutive prime numbers:

The next prime number is:
31

Example 91:

Question:
What is the next number in the series?
1, 4, 16, 64, 256, ___?

Solution:
The series is multiplying by 4 each time:

1 × 4 = 4
4 × 4 = 16
16 × 4 = 64
64 × 4 = 256

So, the next number will be:
256 × 4 = 1024

Example 92:

Question:
What is the next number in the series?
7, 14, 21, 28, 35, ___?

Solution:
The series increases by 7 each time:

14 – 7 = 7
21 – 14 = 7
28 – 21 = 7
35 – 28 = 7

So, the next number will be:
35 + 7 = 42

Example 93:

Question:
What is the next number in the series?
3, 9, 27, 81, 243, ___?

Solution:
The series is multiplying by 3 each time:

3 × 3 = 9
9 × 3 = 27
27 × 3 = 81
81 × 3 = 243

So, the next number will be:
243 × 3 = 729

Example 94:

Question:
What is the next number in the series?
2, 6, 12, 20, 30, ___?

Solution:
The differences between consecutive numbers are increasing by 2 each time:

6 – 2 = 4
12 – 6 = 6
20 – 12 = 8
30 – 20 = 10

The next difference will be 12.
So, the next number will be:
30 + 12 = 42

Example 95:

Question:
What is the next number in the series?
1, 3, 6, 10, 15, ___?

Solution:
The differences between consecutive terms are increasing by 1 each time:

3 – 1 = 2
6 – 3 = 3
10 – 6 = 4
15 – 10 = 5

The next difference will be 6.
So, the next number will be:
15 + 6 = 21

Example 96:

Question:
What is the next number in the series?
7, 14, 28, 56, 112, ___?

Solution:
The series is doubling each time:

7 × 2 = 14
14 × 2 = 28
28 × 2 = 56
56 × 2 = 112

So, the next number will be:
112 × 2 = 224

Example 97:

Question:
What is the next number in the series?
10, 18, 34, 66, 130, ___?

Solution:
The differences between consecutive terms are increasing by 16 each time:

18 – 10 = 8
34 – 18 = 16
66 – 34 = 32
130 – 66 = 64

The next difference will be 128.
So, the next number will be:
130 + 128 = 258

Example 98:

Question:
What is the next number in the series?
2, 5, 10, 17, 26, ___?

Solution:
The differences between consecutive terms are increasing by 2:

5 – 2 = 3
10 – 5 = 5
17 – 10 = 7
26 – 17 = 9

The next difference will be 11.
So, the next number will be:
26 + 11 = 37

Example 99:

Question:
What is the next number in the series?
2, 4, 8, 16, 32, ___?

Solution:
The series is doubling each time:

2 × 2 = 4
4 × 2 = 8
8 × 2 = 16
16 × 2 = 32

So, the next number will be:
32 × 2 = 64

Example 100:

Question:
What is the next number in the series?
5, 15, 30, 50, 75, ___?

Solution:
The differences between consecutive terms are increasing by 5 each time:

15 – 5 = 10
30 – 15 = 15
50 – 30 = 20
75 – 50 = 25

The next difference will be 30.
So, the next number will be:
75 + 30 = 105

Example 101:

Question:
What is the next number in the series?
1, 5, 14, 30, 55, ___?

Solution:
The differences between consecutive terms are increasing by 3 each time:

5 – 1 = 4
14 – 5 = 9
30 – 14 = 16
55 – 30 = 25

The next difference will be 36.
So, the next number will be:
55 + 36 = 91

Example 102:

Question:
What is the next number in the series?
6, 18, 54, 162, 486, ___?

Solution:
The series is multiplying by 3 each time:

6 × 3 = 18
18 × 3 = 54
54 × 3 = 162
162 × 3 = 486

So, the next number will be:
486 × 3 = 1458

Example 103:

Question:
What is the next number in the series?
7, 11, 15, 19, 23, ___?

Solution:
The series increases by 4 each time:

11 – 7 = 4
15 – 11 = 4
19 – 15 = 4
23 – 19 = 4

So, the next number will be:
23 + 4 = 27

Example 104:

Question:
What is the next number in the series?
3, 6, 12, 24, 48, ___?

Solution:
The series is doubling each time:

3 × 2 = 6
6 × 2 = 12
12 × 2 = 24
24 × 2 = 48

So, the next number will be:
48 × 2 = 96

Example 105:

Question:
What is the next number in the series?
10, 20, 40, 80, 160, ___?

Solution:
The series is doubling each time:

10 × 2 = 20
20 × 2 = 40
40 × 2 = 80
80 × 2 = 160

So, the next number will be:
160 × 2 = 320

Example 106:

Question:
What is the next number in the series?
1, 4, 9, 16, 25, ___?

Solution:
These are the squares of consecutive integers:

1 = 1²
4 = 2²
9 = 3²
16 = 4²
25 = 5²

The next number will be:
6² = 36

Example 107:

Question:
What is the next number in the series?
100, 80, 60, 40, 20, ___?

Solution:
The series is decreasing by 20 each time:

100 – 20 = 80
80 – 20 = 60
60 – 20 = 40
40 – 20 = 20

So, the next number will be:
20 – 20 = 0

Example 108:

Question:
What is the next number in the series?
1, 3, 7, 15, 31, ___?

Solution:
The series follows the pattern of doubling and then adding 1:

1 × 2 + 1 = 3
3 × 2 + 1 = 7
7 × 2 + 1 = 15
15 × 2 + 1 = 31

The next number will be:
31 × 2 + 1 = 63

Example 109:

Question:
What is the next number in the series?
5, 10, 20, 40, 80, ___?

Solution:
The series is doubling each time:

5 × 2 = 10
10 × 2 = 20
20 × 2 = 40
40 × 2 = 80

So, the next number will be:
80 × 2 = 160

Example 110:

Question:
What is the next number in the series?
3, 12, 48, 192, 768, ___?

Solution:
The series is multiplying by 4 each time:

3 × 4 = 12
12 × 4 = 48
48 × 4 = 192
192 × 4 = 768

So, the next number will be:
768 × 4 = 3072

Example 111:

Question:
What is the next number in the series?
2, 6, 12, 20, 30, ___?

Solution:
The differences between consecutive terms are increasing by 2 each time:

6 – 2 = 4
12 – 6 = 6
20 – 12 = 8
30 – 20 = 10

The next difference will be 12.
So, the next number will be:
30 + 12 = 42

Example 112:

Question:
What is the next number in the series?
2, 5, 10, 17, 26, ___?

Solution:
The differences between consecutive terms are increasing by 2 each time:

5 – 2 = 3
10 – 5 = 5
17 – 10 = 7
26 – 17 = 9

The next difference will be 11.
So, the next number will be:
26 + 11 = 37

Example 113:

Question:
What is the next number in the series?
5, 9, 13, 17, 21, ___?

Solution:
The series increases by 4 each time:

9 – 5 = 4
13 – 9 = 4
17 – 13 = 4
21 – 17 = 4

So, the next number will be:
21 + 4 = 25

Example 114:

Question:
What is the next number in the series?
7, 11, 15, 19, 23, ___?

Solution:
The series increases by 4 each time:

11 – 7 = 4
15 – 11 = 4
19 – 15 = 4
23 – 19 = 4

So, the next number will be:
23 + 4 = 27

Example 115:

Question:
What is the next number in the series?
2, 4, 6, 8, 10, ___?

Solution:
The series increases by 2 each time:

4 – 2 = 2
6 – 4 = 2
8 – 6 = 2
10 – 8 = 2

So, the next number will be:
10 + 2 = 12

Example 116:

Question:
What is the next number in the series?
1, 3, 9, 27, 81, ___?

Solution:
The series is multiplying by 3 each time:

1 × 3 = 3
3 × 3 = 9
9 × 3 = 27
27 × 3 = 81

So, the next number will be:
81 × 3 = 243

Example 117:

Question:
What is the next number in the series?
3, 7, 15, 31, 63, ___?

Solution:
The series follows the pattern of doubling and then adding 1:

3 × 2 + 1 = 7
7 × 2 + 1 = 15
15 × 2 + 1 = 31
31 × 2 + 1 = 63

The next number will be:
63 × 2 + 1 = 127

Example 118:

Question:
What is the next number in the series?
10, 20, 40, 80, 160, ___?

Solution:
The series is doubling each time:

10 × 2 = 20
20 × 2 = 40
40 × 2 = 80
80 × 2 = 160

So, the next number will be:
160 × 2 = 320

Example 119:

Question:
What is the next number in the series?
2, 10, 30, 68, 130, ___?

Solution:
The differences between consecutive terms are increasing by 8 each time:

10 – 2 = 8
30 – 10 = 20
68 – 30 = 38
130 – 68 = 62

The next difference will be 92.
So, the next number will be:
130 + 92 = 222

Example 120:

Question:
What is the next number in the series?
2, 5, 10, 17, 26, ___?

Solution:
The differences between consecutive terms are increasing by 2 each time:

5 – 2 = 3
10 – 5 = 5
17 – 10 = 7
26 – 17 = 9

The next difference will be 11.
So, the next number will be:
26 + 11 = 37

Example 121:

Question:
What is the next number in the series?
5, 9, 17, 33, 65, ___?

Solution:
The differences between consecutive terms are doubling each time:

9 – 5 = 4
17 – 9 = 8
33 – 17 = 16
65 – 33 = 32

The next difference will be 64.
So, the next number will be:
65 + 64 = 129

Example 122:

Question:
What is the next number in the series?
1, 2, 6, 24, 120, ___?

Solution:
The series is following the pattern of factorials:

1 = 1!
2 = 2!
6 = 3!
24 = 4!
120 = 5!

The next number will be:
6! = 720

Example 123:

Question:
What is the next number in the series?
4, 9, 19, 39, 79, ___?

Solution:
The differences between consecutive terms are:

9 – 4 = 5
19 – 9 = 10
39 – 19 = 20
79 – 39 = 40

The next difference will be 80.
So, the next number will be:
79 + 80 = 159

Example 124:

Question:
What is the next number in the series?
2, 6, 12, 20, 30, ___?

Solution:
The differences between consecutive terms are increasing by 2 each time:

6 – 2 = 4
12 – 6 = 6
20 – 12 = 8
30 – 20 = 10

The next difference will be 12.
So, the next number will be:
30 + 12 = 42

Example 125:

Question:
What is the next number in the series?
1, 5, 14, 30, 55, ___?

Solution:
The differences between consecutive terms are:

5 – 1 = 4
14 – 5 = 9
30 – 14 = 16
55 – 30 = 25

The next difference will be 36.
So, the next number will be:
55 + 36 = 91

Example 126:

Question:
What is the next number in the series?
6, 15, 36, 77, 150, ___?

Solution:
The differences between consecutive terms are:

15 – 6 = 9
36 – 15 = 21
77 – 36 = 41
150 – 77 = 73

The next difference will be 105.
So, the next number will be:
150 + 105 = 255

Example 127:

Question:
What is the next number in the series?
1, 1, 2, 6, 24, ___?

Solution:
This is a series of factorial numbers:

1 = 0!
1 = 1!
2 = 2!
6 = 3!
24 = 4!

The next number will be:
5! = 120

Example 128:

Question:
What is the next number in the series?
10, 9, 7, 4, 0, ___?

Solution:
The differences between consecutive terms are decreasing by 1 each time:

9 – 10 = -1
7 – 9 = -2
4 – 7 = -3
0 – 4 = -4

The next difference will be -5.
So, the next number will be:
0 – 5 = -5

Example 129:

Question:
What is the next number in the series?
3, 9, 27, 81, 243, ___?

Solution:
The series is multiplying by 3 each time:

3 × 3 = 9
9 × 3 = 27
27 × 3 = 81
81 × 3 = 243

So, the next number will be:
243 × 3 = 729

Example 130:

Question:
What is the next number in the series?
5, 11, 23, 47, 95, ___?

Solution:
The differences between consecutive terms are:

11 – 5 = 6
23 – 11 = 12
47 – 23 = 24
95 – 47 = 48

The next difference will be 96.
So, the next number will be:
95 + 96 = 191

Example 131:

Question:
What is the next number in the series?
2, 8, 30, 120, 480, ___?

Solution:
The series is multiplying by 4, 3, 4, 3, and so on:

2 × 4 = 8
8 × 3 = 30
30 × 4 = 120
120 × 3 = 480

So, the next number will be:
480 × 4 = 1920

Example 132:

Question:
What is the next number in the series?
2, 3, 7, 15, 31, ___?

Solution:
The series is doubling and then adding 1:

2 × 2 + 1 = 3
3 × 2 + 1 = 7
7 × 2 + 1 = 15
15 × 2 + 1 = 31

The next number will be:
31 × 2 + 1 = 63

Example 133:

Question:
What is the next number in the series?
1, 1, 2, 6, 24, ___?

Solution:
The series is following the factorial pattern:

1 = 0!
1 = 1!
2 = 2!
6 = 3!
24 = 4!

The next number will be:
5! = 120

Example 134:

Question:
What is the next number in the series?
2, 6, 12, 20, 30, ___?

Solution:
The differences between consecutive terms are increasing by 2 each time:

6 – 2 = 4
12 – 6 = 6
20 – 12 = 8
30 – 20 = 10

The next difference will be 12.
So, the next number will be:
30 + 12 = 42

Example 135:

Question:
What is the next number in the series?
2, 5, 10, 17, 26, ___?

Solution:
The differences between consecutive terms are increasing by 2 each time:

5 – 2 = 3
10 – 5 = 5
17 – 10 = 7
26 – 17 = 9

The next difference will be 11.
So, the next number will be:
26 + 11 = 37

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