Number Series

Solved Questions on Number Series

1. Find the missing value in the series given below: 1, 4, 9, 16, __, 36, 49.

a) 17
b) 19
c) 22
d) 25

Answer: d) 25

Explanation: Given series is 1, 4, 9, 16, __, 36, 49.
The given series is known as the series of square numbers.

From the above series, we can write 1², 2², 3², 4², 5², 6², 7², …
So, the missing number in the series is 5² = 25.

2. What number should come in the blank?

a) 3
b) 5
c) 7
d) 9

Answer: d) 9

Explanation:

3. Look carefully for the series, and then choose which pair of numbers comes next.

28, 25, 5, 21, 18, 5, 14, __, ___

a) 11, 5
b) 10, 7
c) 5, 10
d) 12, 13

Answer: a) 11, 5

Explanation: This is a subtraction series that alternates between subtracting 3 and 4 repeatedly. Every third number in the series is replaced with a random number, 5, which serves as an interpolation.

4. What is the next number in the given sequence –12, –7, –2, 3, ….?

a) 5
b) 7
c) 8
d) 11

Answer: c) 8

Explanation: Given sequence is –12, –7, –2, 3, ….
We know that an addition sequence series is a sequence where each term is obtained by adding a constant number to the previous term (Except the first term).

Here, the constant number is called a “common difference”, and it is represented by d.
d = a₂ – a₁ = (–7) – (–12) = (–7) + 12 = 5
The next number after 3 is obtained by adding a common difference (d=5).

So, the next number is 3 + 5 = 8.

5. How many dots should be there in the next term in the given series?

a) 7
b) 8
c) 9
d) 10

Answer: d) 10

Explanation:

By the observation of above figure, we can identify the number of dots as 10.

Practice Questions on Numbers Series

1. Complete the series: 2, 4, 8, 16, 32, ____

a) 35
b) 42
c) 56
d) 64

Answer: d) 64

2. Look at this series: 8, 22, 8, 28, 8, ... What number should come next?

a) 9
b) 29
c) 34
d) 36

Answer: c) 34

3. Johnny used the rule "double the number" to create the series below. 3, 6, 12, 24, ... Which of the number is part of the series?

a) 25
b) 32
c) 36
d) 48

Answer: d) 48

4. What is the rule of the following series? 10, 7, 4, 1….

a) Add 3
b) Subtract 3
c) Multiply by 3
d) Divide by 3

Answer: b) Subtract 3

5. Which number will come in place of question mark? 5, 7, 12, 6, 8, 14, 7, (?), 16, 8, 10, 18.

a) 7
b) 9
c) 11
d) 13

Answer: b) 9

6. Complete the series: 1, 3, 9, 27, 81, ____.

a) 149
b) 189
c) 243
d) 289

Answer: c) 243

7. What will be the next term of given series? 121, 144, 169, ____.

a) 172
b) 184
c) 192
d) 196

Answer: d) 196

8. Complete the following series: 1, 2, 6, 24, 120, ____.

a) 720
b) 630
c) 540
d) 482

Answer: a) 720

9. Complete the following series: 3, 2,1, 0, -1, ____.

a) -2
b) 2
c) 3
d) -3

Answer: a) -2

10. Complete the following series:

1² + 3² + 5² = 9
1² + 3² + 5² + 7² = 16
1² + 3² + 5² + 7² + 9² = 25
1² + 3²+ 5² + 7² + 9² + 11² + 13² + 15² + 17² + 19² + 21² = ?

a) 144
b) 121
c) 256
d) 100

Answer: b) 121