Number Series Completion MCQ – Reasoning Questions and Answers

1. Complete the series: 2, 4, 8, 16, ?

a) 24

b) 28

c) 32

d) 36

Answer:

c) 32

Explanation:

Each number is multiplied by 2. So, 16 * 2 = 32.

2. Find the missing number: 5, 10, 15, ?, 25

a) 18

b) 20

c) 22

d) 24

Answer:

b) 20

Explanation:

The pattern is adding 5 each time.

3. Complete the series: 3, 9, 27, ?

a) 54

b) 63

c) 81

d) 108

Answer:

c) 81

Explanation:

Each number is multiplied by 3.

4. Find the missing number: 10, 20, 40, 80, ?

a) 120

b) 140

c) 160

d) 200

Answer:

c) 160

Explanation:

Each number is doubling the previous one.

5. Complete the series: 1, 4, 9, 16, ?

a) 20

b) 25

c) 36

d) 49

Answer:

b) 25

Explanation:

The series represents square numbers. 5^2 = 25.

6. Find the missing number: 2, 3, 5, 8, ?

a) 10

b) 11

c) 12

d) 13

Answer:

d) 13

Explanation:

The pattern is adding the previous two numbers (3+5, 5+8).

7. Complete the series: 100, 90, 80, ?, 60

a) 65

b) 70

c) 75

d) 85

Answer:

b) 70

Explanation:

The pattern is subtracting 10 each time.

8. Find the missing number: 7, 14, 28, 56, ?

a) 70

b) 84

c) 98

d) 112

Answer:

d) 112

Explanation:

The series is each number times 2.

9. Complete the series: 1, 1, 2, 3, 5, ?

a) 7

b) 8

c) 9

d) 10

Answer:

b) 8

Explanation:

This is the Fibonacci sequence, where each number is the sum of the two preceding ones.

10. Find the missing number: 2, 4, 8, ?, 32

a) 14

b) 16

c) 18

d) 20

Answer:

b) 16

Explanation:

The pattern is each number multiplied by 2.

11. Complete the series: 3, 6, 12, 24, ?

a) 36

b) 42

c) 48

d) 54

Answer:

c) 48

Explanation:

Each number is multiplied by 2.

12. Find the missing number: 1, 4, 9, ?, 25

a) 14

b) 16

c) 18

d) 20

Answer:

b) 16

Explanation:

The series is square numbers. 4^2 = 16.

13. Complete the series: 11, 22, 33, 44, ?

a) 55

b) 65

c) 75

d) 85

Answer:

a) 55

Explanation:

The pattern is adding 11 each time.

14. Find the missing number: 5, 10, 20, 40, ?, 160

a) 60

b) 70

c) 80

d) 100

Answer:

c) 80

Explanation:

Each number is doubling the previous one.

15. Complete the series: 2, 6, 18, 54, ?

a) 108

b) 162

c) 216

d) 324

Answer:

b) 162

Explanation:

Each number is multiplied by 3.

16. Find the missing number: 1, 8, 27, ?, 125

a) 36

b) 48

c) 64

d) 81

Answer:

c) 64

Explanation:

The series is cube numbers. 4^3 = 64.

17. Complete the series: 3, 9, 27, 81, ?

a) 144

b) 162

c) 243

d) 324

Answer:

c) 243

Explanation:

Each number is multiplied by 3.

18. Find the missing number: 4, 16, 64, ?, 1024

a) 128

b) 256

c) 512

d) 768

Answer:

b) 256

Explanation:

The pattern is each number times 4.

19. Complete the series: 5, 11, 17, 23, ?

a) 27

b) 29

c) 31

d) 35

Answer:

b) 29

Explanation:

The pattern is adding 6 each time.

20. Find the missing number: 10, 13, 16, 19, ?, 25

a) 21

b) 22

c) 23

d) 24

Answer:

b) 22

Explanation:

The pattern is adding 3 each time.

21. Complete the series: 12, 24, 48, 96, ?

a) 120

b) 144

c) 168

d) 192

Answer:

d) 192

Explanation:

Each number is doubled.

22. Find the missing number: 1, 3, 7, 15, ?

a) 23

b) 27

c) 31

d) 35

Answer:

c) 31

Explanation:

The pattern is 2^n – 1.

23. Complete the series: 2, 3, 5, 7, ?

a) 9

b) 10

c) 11

d) 13

Answer:

c) 11

Explanation:

The series consists of prime numbers.

24. Find the missing number: 20, 40, 60, ?, 100

a) 70

b) 80

c) 90

d) 110

Answer:

b) 80

Explanation:

The pattern is adding 20 each time.

25. Complete the series: 6, 12, 24, 48, ?

a) 72

b) 84

c) 96

d) 108

Answer:

c) 96

Explanation:

Each number is doubled.

26. Find the missing number: 3, 6, 9, 12, ?, 18

a) 13

b) 14

c) 15

d) 16

Answer:

c) 15

Explanation:

The pattern is adding 3 each time.

27. Complete the series: 1, 8, 27, 64, ?

a) 100

b) 125

c) 150

d) 175

Answer:

b) 125

Explanation:

The series is cube numbers. 5^3 = 125.

28. Find the missing number: 1, 2, 4, 8, 16, ?

a) 24

b) 28

c) 32

d) 36

Answer:

c) 32

Explanation:

Each number is doubled.

29. Complete the series: 2, 6, 12, 20, ?

a) 28

b) 30

c) 32

d) 35

Answer:

b) 30

Explanation:

The pattern is n(n+1).

30. Find the missing number: 100, 200, 300, ?, 500

a) 350

b) 400

c) 450

d) 600

Answer:

b) 400

Explanation:

The pattern is adding 100 each time.

31. Complete the series: 4, 7, 11, 16, ?

a) 20

b) 22

c) 24

d) 26

Answer:

b) 22

Explanation:

The series is increasing by consecutive odd numbers.

32. Find the missing number: 5, 10, 20, 40, 80, ?

a) 120

b) 140

c) 160

d) 180

Answer:

c) 160

Explanation:

Each number is doubled.

33. Complete the series: 3, 9, 27, 81, 243, ?

a) 486

b) 729

c) 972

d) 1024

Answer:

b) 729

Explanation:

Each number is multiplied by 3.

34. Find the missing number: 1, 1, 2, 6, 24, ?

a) 100

b) 110

c) 120

d) 130

Answer:

c) 120

Explanation:

The series is factorial numbers.

35. Complete the series: 2, 4, 7, 11, ?

a) 14

b) 15

c) 16

d) 18

Answer:

c) 16

Explanation:

The pattern is increasing by 2, 3, 4, and so on.

36. Find the missing number: 5, 7, 11, 17, ?

a) 23

b) 25

c) 27

d) 31

Answer:

a) 23

Explanation:

The series consists of consecutive prime numbers.

37. Complete the series: 10, 9, 8, 7, ?

a) 5

b) 6

c) 7

d) 8

Answer:

b) 6

Explanation:

The series is decreasing by 1 each time.

38. Find the missing number: 1, 4, 9, 16, 25, ?

a) 30

b) 35

c) 36

d) 49

Answer:

c) 36

Explanation:

The series is square numbers. 6^2 = 36.

39. Complete the series: 1, 2, 6, 24, 120, ?

a) 600

b) 720

c) 840

d) 960

Answer:

b) 720

Explanation:

The series is factorial numbers.

40. Find the missing number: 2, 6, 18, 54, ?

a) 108

b) 162

c) 216

d) 324

Answer:

b) 162

Explanation:

Each number is multiplied by 3.

41. Complete the series: 3, 8, 15, 24, ?

a) 30

b) 34

c) 35

d) 40

Answer:

c) 35

Explanation:

The pattern is n^2+1.

42. Find the missing number: 100, 90, 80, ?, 60

a) 65

b) 70

c) 75

d) 85

Answer:

b) 70

Explanation:

The series is decreasing by 10 each time.

43. Complete the series: 1, 1, 2, 3, 5, 8, ?

a) 10

b) 11

c) 13

d) 15

Answer:

c) 13

Explanation:

This is the Fibonacci sequence, where each number is the sum of the two preceding ones.

44. Find the missing number: 2, 3, 5, 7, 11, ?

a) 13

b) 15

c) 17

d) 19

Answer:

a) 13

Explanation:

The series consists of prime numbers.

45. Complete the series: 12, 14, 18, 24, ?

a) 30

b) 32

c) 34

d) 36

Answer:

b) 32

Explanation:

The pattern is increasing by 2, 4, 6, and so on.

46. Find the missing number: 1, 8, 27, 64, 125, ?

a) 196

b) 216

c) 256

d) 343

Answer:

b) 216

Explanation:

The series is cube numbers. 6^3 = 216.

47. Complete the series: 1, 2, 4, 7, 11, ?

a) 15

b) 16

c) 17

d) 18

Answer:

b) 16

Explanation:

The pattern is adding 1, 2, 3, 4, and so on.

48. Find the missing number: 3, 6, 12, 24, 48, ?

a) 72

b) 84

c) 96

d) 108

Answer:

c) 96

Explanation:

Each number is doubled.

49. Complete the series: 2, 3, 5, 8, 12, ?

a) 15

b) 17

c) 18

d) 20

Answer:

b) 17

Explanation:

The pattern is adding 1, 2, 3, 4, and so on.

50. Find the missing number: 5, 11, 17, 23, 29, ?

a) 31

b) 35

c) 37

d) 41

Answer:

b) 35

Explanation:

The series is increasing by 6 each time.