Series Test MCQs (1–150)

1. What comes next in the series: 2, 4, 6, 8, ?
A) 9
B) 10
C) 12
D) 14
👉 Explanation: The series increases by +2 → next = 10, but sequence shows even numbers → correct = 10. (Fix: If mistake intended, correct = 10).

2. Find the missing number: 5, 10, 20, 40, ?
A) 60
B) 70
C) 90
D) 80
👉 Explanation: Each term is ×2.

3. Series: 1, 4, 9, 16, 25, ?
A) 30
B) 32
C) 36
D) 40
👉 Explanation: Square numbers (1², 2², 3², 4², 5², 6²).

4. What comes next: 2, 3, 5, 7, 11, ?
A) 13
B) 17
C) 19
D) 23
👉 Explanation: Prime number series. Next = 13.

5. Series: 100, 90, 80, 70, ?
A) 60
B) 50
C) 40
D) 30
👉 Explanation: Decreasing by 10.

6. What comes next: 1, 2, 4, 8, 16, ?
A) 30
B) 31
C) 32
D) 36
👉 Explanation: ×2 each step.

7. Series: 1, 3, 6, 10, 15, ?
A) 18
B) 21
C) 22
D) 25
👉 Explanation: Triangular numbers.

8. Find the missing: 0, 1, 1, 2, 3, 5, ?
A) 6
B) 8
C) 9
D) 10
👉 Explanation: Fibonacci series.

9. Series: 81, 64, 49, 36, ?
A) 28
B) 30
C) 25
D) 20
👉 Explanation: Perfect squares in reverse (9², 8², 7², 6², 5²).

10. What comes next: 11, 22, 33, 44, ?
A) 50
B) 55
C) 66
D) 77
👉 Explanation: Adding 11 each step.

11. Series: 3, 6, 12, 24, ?
A) 36
B) 40
C) 48
D) 54
👉 Explanation: ×2 each time.

12. Find the missing: 2, 6, 12, 20, 30, ?
A) 36
B) 40
C) 42
D) 46
👉 Explanation: Pattern = n(n+1).

13. What comes next: 13, 26, 39, 52, ?
A) 55
B) 60
C) 65
D) 70
👉 Explanation: Adding 13.

14. Series: 121, 144, 169, ?
A) 180
B) 190
C) 196
D) 200
👉 Explanation: Squares (11², 12², 13², 14²).

15. Next number: 2, 5, 10, 17, 26, ?
A) 34
B) 35
C) 37
D) 40
👉 Explanation: +3, +5, +7, +9 → next +11 = 37.

16. Series: 1, 8, 27, 64, ?
A) 100
B) 120
C) 125
D) 150
👉 Explanation: Cubes (1³, 2³, 3³, 4³, 5³).

17. Find the missing: 7, 14, 28, 56, ?
A) 100
B) 112
C) 120
D) 124
👉 Explanation: ×2 each time.

18. Series: 19, 37, 55, 73, ?
A) 88
B) 90
C) 91
D) 93
👉 Explanation: Adding 18 each time.

19. What comes next: 4, 9, 16, 25, ?
A) 30
B) 36
C) 40
D) 45
👉 Explanation: Perfect squares.

20. Series: 2, 12, 30, 56, 90, ?
A) 120
B) 132
C) 140
D) 150
👉 Explanation: Pattern = n(n+1)(n+2).

21. Find the missing: 3, 9, 27, 81, ?
A) 200
B) 220
C) 243
D) 300
👉 Explanation: ×3 each time.

22. Series: 10, 20, 30, 40, ?
A) 45
B) 48
C) 50
D) 60
👉 Explanation: +10 pattern.

23. What comes next: 1, 4, 8, 13, 19, ?
A) 24
B) 25
C) 26
D) 28
👉 Explanation: +3, +4, +5, +6 → next +7 = 26.

24. Series: 2, 5, 10, 17, 26, ?
A) 34
B) 35
C) 37
D) 40
👉 Explanation: Increasing by consecutive odd numbers.

25. Find missing: 125, 64, 27, 8, ?
A) 0
B) 1
C) 2
D) 3
👉 Explanation: Reverse cubes (5³, 4³, 3³, 2³, 1³).

26. Series: 11, 22, 33, 44, ?
A) 48
B) 50
C) 55
D) 60
👉 Explanation: +11 each step.

27. Next term: 4, 16, 36, 64, ?
A) 80
B) 90
C) 100
D) 110
👉 Explanation: Squares of even numbers (2², 4², 6², 8², 10²).

28. Series: 3, 6, 12, 24, ?
A) 40
B) 44
C) 48
D) 50
👉 Explanation: ×2 pattern.

29. What comes next: 2, 3, 5, 9, 17, ?
A) 25
B) 33
C) 35
D) 37
👉 Explanation: Doubled previous – 1.

30. Series: 21, 18, 15, 12, ?
A) 11
B) 9
C) 8
D) 7
👉 Explanation: –3 each step.

31. Next number: 6, 11, 21, 36, ?
A) 45
B) 46
C) 56
D) 60
👉 Explanation: Differences = 5, 10, 15, 20 → next 56.

32. Series: 8, 27, 64, 125, ?
A) 150
B) 160
C) 216
D) 225
👉 Explanation: Cubes (2³, 3³, 4³, 5³, 6³).

33. Find missing: 2, 6, 12, 20, ?
A) 28
B) 30
C) 32
D) 34
👉 Explanation: n(n+1).

34. Series: 1, 2, 6, 24, 120, ?
A) 480
B) 720
C) 840
D) 900
👉 Explanation: Factorials (1!, 2!, 3!, 4!, 5!, 6!).

35. What comes next: 100, 121, 144, 169, ?
A) 175
B) 180
C) 196
D) 200
👉 Explanation: Squares (10², 11², 12², 13², 14²).

36. Series: 9, 18, 27, 36, ?
A) 42
B) 45
C) 48
D) 50
👉 Explanation: +9 each step.

37. Next number: 2, 5, 10, 17, 26, ?
A) 35
B) 37
C) 38
D) 39
👉 Explanation: +3, +5, +7, +9, +11.

38. Series: 1, 4, 27, 256, ?
A) 625
B) 3125
C) 4096
D) 1000
👉 Explanation: Powers (1¹, 2², 3³, 4⁴, 5⁵).

39. Find missing: 50, 45, 40, 35, ?
A) 32
B) 33
C) 30
D) 28
👉 Explanation: Decreasing by 5.

40. Series: 2, 3, 5, 7, 11, 13, ?
A) 15
B) 17
C) 19
D) 21
👉 Explanation: Prime numbers.

41. Find missing: 1, 2, 6, 24, ?
A) 60
B) 100
C) 120
D) 150
👉 Explanation: Factorials → 1!, 2!, 3!, 4!, 5! = 120.

42. Series: 7, 14, 28, 56, ?
A) 90
B) 100
C) 112
D) 120
👉 Explanation: ×2 each step.

43. Next number: 3, 12, 27, 48, 75, ?
A) 90
B) 95
C) 108
D) 120
👉 Explanation: n³ + n.

44. Find missing: 1, 8, 27, 64, ?
A) 100
B) 125
C) 150
D) 200
👉 Explanation: Cubes (1³, 2³, 3³, 4³, 5³).

45. Series: 5, 10, 20, 40, ?
A) 60
B) 70
C) 80
D) 90
👉 Explanation: ×2.

46. What comes next: 1, 1, 2, 3, 5, 8, ?
A) 10
B) 11
C) 13
D) 15
👉 Explanation: Fibonacci series.

47. Series: 4, 9, 16, 25, ?
A) 30
B) 36
C) 49
D) 50
👉 Explanation: Squares (2², 3², 4², 5², 6²).

48. Next number: 12, 24, 48, 96, ?
A) 120
B) 150
C) 192
D) 200
👉 Explanation: ×2.

49. Series: 31, 28, 25, 22, ?
A) 20
B) 19
C) 18
D) 17
👉 Explanation: –3 each step.

50. What comes next: 3, 6, 11, 18, 27, ?
A) 32
B) 38
C) 40
D) 42
👉 Explanation: +3, +5, +7, +9, +11.

51. Find missing: 2, 5, 10, 17, 26, ?
A) 33
B) 37
C) 39
D) 41
👉 Explanation: Differences +3, +5, +7, +9, +11.

52. Series: 121, 144, 169, ?
A) 180
B) 185
C) 196
D) 200
👉 Explanation: Squares (11², 12², 13², 14²).

53. Next term: 0, 1, 1, 2, 3, 5, ?
A) 6
B) 7
C) 8
D) 9
👉 Explanation: Fibonacci series.

54. Find missing: 50, 100, 150, 200, ?
A) 230
B) 250
C) 260
D) 270
👉 Explanation: +50 each step.

55. Series: 2, 4, 8, 16, 32, ?
A) 50
B) 60
C) 64
D) 70
👉 Explanation: Powers of 2.

56. Next number: 11, 13, 17, 19, 23, ?
A) 25
B) 27
C) 29
D) 31
👉 Explanation: Prime numbers.

57. Series: 1, 4, 9, 16, 25, ?
A) 30
B) 32
C) 36
D) 40
👉 Explanation: Perfect squares.

58. What comes next: 0, 3, 8, 15, 24, ?
A) 28
B) 35
C) 40
D) 45
👉 Explanation: n² – 1.

59. Series: 7, 14, 21, 28, ?
A) 32
B) 35
C) 36
D) 37
👉 Explanation: +7 each step.

60. Find missing: 10, 20, 40, 80, ?
A) 100
B) 120
C) 160
D) 200
👉 Explanation: ×2.

61. Series: 1, 2, 4, 7, 11, 16, ?
A) 20
B) 22
C) 24
D) 25
👉 Explanation: +1, +2, +3, +4, +5 → next +6.

62. Next number: 9, 18, 36, 72, ?
A) 90
B) 100
C) 144
D) 150
👉 Explanation: ×2.

63. Series: 4, 6, 9, 13, 18, ?
A) 21
B) 24
C) 25
D) 27
👉 Explanation: +2, +3, +4, +5, next +6 = 24.

64. What comes next: 5, 25, 125, 625, ?
A) 2500
B) 3125
C) 5000
D) 6000
👉 Explanation: Powers of 5.

65. Find missing: 121, 100, 81, 64, ?
A) 45
B) 49
C) 55
D) 60
👉 Explanation: Squares in reverse order.

66. Series: 2, 6, 12, 20, ?
A) 26
B) 30
C) 32
D) 34
👉 Explanation: n(n+1).

67. Next number: 1, 2, 6, 24, 120, ?
A) 300
B) 400
C) 720
D) 900
👉 Explanation: Factorials.

68. Find missing: 15, 30, 60, 120, ?
A) 180
B) 240
C) 250
D) 300
👉 Explanation: ×2.

69. Series: 3, 6, 12, 24, 48, ?
A) 90
B) 96
C) 100
D) 120
👉 Explanation: ×2.

70. What comes next: 13, 26, 39, 52, ?
A) 60
B) 62
C) 65
D) 70
👉 Explanation: +13.

71. Series: 1, 8, 27, 64, 125, ?
A) 180
B) 216
C) 225
D) 230
👉 Explanation: Cubes (6³ = 216).

72. Next number: 2, 4, 8, 14, 22, ?
A) 28
B) 32
C) 34
D) 36
👉 Explanation: +2, +4, +6, +8, next +10 = 32.

73. Find missing: 11, 22, 44, 88, ?
A) 120
B) 176
C) 180
D) 200
👉 Explanation: ×2.

74. Series: 6, 12, 24, 48, ?
A) 90
B) 96
C) 192
D) 200
👉 Explanation: ×2, ×2, ×2, next ×2 = 96. (Oops correction: Answer is 96, not 192).

75. What comes next: 3, 9, 27, 81, ?
A) 200
B) 220
C) 243
D) 250
👉 Explanation: Powers of 3.

76. Series: 17, 34, 51, 68, ?
A) 72
B) 74
C) 85
D) 90
👉 Explanation: +17.

77. Next number: 5, 10, 17, 26, ?
A) 32
B) 37
C) 39
D) 41
👉 Explanation: +5, +7, +9, +11.

78. Find missing: 25, 49, 81, 121, ?
A) 140
B) 144
C) 169
D) 196
👉 Explanation: Squares of odd numbers (5², 7², 9², 11², 13²).

79. Series: 8, 16, 24, 32, ?
A) 38
B) 40
C) 42
D) 44
👉 Explanation: +8.

80. What comes next: 20, 18, 16, 14, ?
A) 11
B) 12
C) 12
D) 10
👉 Explanation: –2 each step.

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81. Series: 1, 4, 7, 10, ?
A) 11
B) 13
C) 15
D) 16
👉 Explanation: +3.

82. Next number: 9, 16, 25, 36, ?
A) 40
B) 49
C) 50
D) 64
👉 Explanation: Perfect squares.

83. Find missing: 2, 4, 12, 48, ?
A) 100
B) 120
C) 240
D) 250
👉 Explanation: ×2, ×3, ×4, ×5.

84. Series: 100, 90, 80, 70, ?
A) 50
B) 55
C) 60
D) 65
👉 Explanation: –10 each step.

85. What comes next: 1, 3, 9, 27, ?
A) 60
B) 70
C) 81
D) 90
👉 Explanation: Powers of 3.

86. Series: 4, 8, 16, 32, ?
A) 60
B) 64
C) 70
D) 72
👉 Explanation: ×2 each step.

87. Next number: 7, 21, 63, 189, ?
A) 500
B) 567
C) 600
D) 700
👉 Explanation: ×3.

88. Find missing: 2, 3, 5, 7, 11, ?
A) 13
B) 13
C) 15
D) 17
👉 Explanation: Prime numbers.

89. Series: 15, 30, 60, 120, ?
A) 150
B) 180
C) 240
D) 300
👉 Explanation: ×2.

90. What comes next: 19, 38, 57, 76, ?
A) 90
B) 94
C) 95
D) 100
👉 Explanation: +19.

91. Series: 1, 2, 4, 8, 16, ?
A) 24
B) 32
C) 36
D) 40
👉 Explanation: Powers of 2.

92. Next number: 13, 26, 52, 104, ?
A) 150
B) 180
C) 208
D) 250
👉 Explanation: ×2.

93. Find missing: 6, 12, 24, 48, ?
A) 90
B) 100
C) 96
D) 120
👉 Explanation: ×2.

94. Series: 100, 81, 64, 49, ?
A) 30
B) 35
C) 36
D) 40
👉 Explanation: Perfect squares in reverse order.

95. What comes next: 2, 6, 18, 54, ?
A) 100
B) 150
C) 162
D) 200
👉 Explanation: ×3.

96. Series: 11, 22, 44, 88, ?
A) 132
B) 150
C) 176
D) 200
👉 Explanation: ×2.

97. Next number: 3, 6, 12, 24, ?
A) 36
B) 40
C) 48
D) 60
👉 Explanation: ×2.

98. Find missing: 25, 50, 75, 100, ?
A) 110
B) 125
C) 130
D) 140
👉 Explanation: +25.

99. Series: 2, 9, 28, 65, ?
A) 120
B) 126
C) 135
D) 140
👉 Explanation: n³ + 1.

100. What comes next: 5, 15, 45, 135, ?
A) 300
B) 350
C) 405
D) 450
👉 Explanation: ×3.

101. Find the missing term: 3, 6, 12, 24, ?
A) 40
B) 42
C) 48
D) 50
👉 Explanation: Each term ×2.

102. Series: 11, 22, 44, 88, ?
A) 150
B) 160
C) 176
D) 180
👉 Explanation: ×2 each step.

103. What comes next: 1, 3, 9, 27, ?
A) 72
B) 81
C) 90
D) 99
👉 Explanation: Powers of 3.

104. Series: 10, 13, 16, 19, ?
A) 20
B) 22
C) 24
D) 25
👉 Explanation: +3 each step.

105. Find the missing: 5, 10, 20, 40, ?
A) 60
B) 70
C) 80
D) 90
👉 Explanation: ×2 pattern.

106. Series: 2, 5, 10, 17, 26, ?
A) 32
B) 34
C) 37
D) 40
👉 Explanation: +3, +5, +7, +9, +11.

107. Next number: 4, 9, 16, 25, ?
A) 30
B) 35
C) 36
D) 40
👉 Explanation: Squares of consecutive numbers.

108. Series: 64, 32, 16, 8, ?
A) 2
B) 4
C) 6
D) 10
👉 Explanation: ÷2 each step.

109. Find missing: 7, 14, 28, 56, ?
A) 90
B) 100
C) 112
D) 120
👉 Explanation: ×2 each time.

110. Series: 3, 12, 48, 192, ?
A) 576
B) 768
C) 800
D) 960
👉 Explanation: ×4 each time.

111. What comes next: 1, 8, 27, 64, ?
A) 100
B) 110
C) 125
D) 150
👉 Explanation: Cubes (1³, 2³, 3³, 4³, 5³).

112. Series: 20, 19, 17, 14, ?
A) 12
B) 10
C) 9
D) 8
👉 Explanation: –1, –2, –3, –4…

113. Find missing: 121, 144, 169, 196, ?
A) 210
B) 215
C) 225
D) 230
👉 Explanation: Squares (11², 12², 13², 14², 15²).

114. Series: 15, 30, 60, 120, ?
A) 180
B) 200
C) 240
D) 260
👉 Explanation: ×2 each step.

115. Next number: 5, 25, 125, ?
A) 525
B) 600
C) 625
D) 700
👉 Explanation: Powers of 5.

116. Series: 9, 18, 36, 72, ?
A) 90
B) 100
C) 144
D) 150
👉 Explanation: ×2 pattern.

117. What comes next: 2, 4, 8, 16, ?
A) 24
B) 28
C) 32
D) 36
👉 Explanation: ×2 pattern.

118. Series: 19, 38, 76, 152, ?
A) 250
B) 280
C) 304
D) 320
👉 Explanation: ×2 each step.

119. Find missing: 50, 60, 70, 80, ?
A) 85
B) 88
C) 90
D) 92
👉 Explanation: +10 each step.

120. Series: 2, 6, 12, 20, ?
A) 24
B) 26
C) 30
D) 32
👉 Explanation: n(n+1).

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121. What comes next: 17, 34, 68, 136, ?
A) 250
B) 272
C) 280
D) 300
👉 Explanation: ×2 each step.

122. Series: 81, 64, 49, 36, ?
A) 20
B) 25
C) 30
D) 32
👉 Explanation: Squares (9², 8², 7², 6², 5²).

123. Find missing: 5, 10, 15, 20, ?
A) 22
B) 23
C) 25
D) 26
👉 Explanation: +5 each step.

124. Series: 3, 5, 7, 11, 13, ?
A) 14
B) 15
C) 17
D) 18
👉 Explanation: Prime numbers.

125. Next number: 2, 9, 28, 65, ?
A) 120
B) 126
C) 130
D) 136
👉 Explanation: Cubes + 1 (1³+1, 2³+1, 3³+1, 4³+1, 5³+1).

126. Series: 14, 28, 56, 112, ?
A) 200
B) 210
C) 224
D) 240
👉 Explanation: ×2 pattern.

127. Find missing: 121, 100, 81, 64, ?
A) 40
B) 45
C) 49
D) 50
👉 Explanation: Squares (11², 10², 9², 8², 7²).

128. Series: 5, 15, 45, 135, ?
A) 350
B) 360
C) 405
D) 450
👉 Explanation: ×3 each step.

129. Next number: 6, 12, 18, 24, ?
A) 28
B) 30
C) 32
D) 34
👉 Explanation: +6 each step.

130. Series: 2, 3, 6, 18, ?
A) 36
B) 54
C) 60
D) 72
👉 Explanation: ×1.5, ×2, ×3, ×3.

131. Find missing: 25, 50, 100, 200, ?
A) 300
B) 350
C) 400
D) 450
👉 Explanation: ×2 each step.

132. Series: 2, 4, 16, 256, ?
A) 1000
B) 65536
C) 4096
D) 10000
👉 Explanation: Powers (2, 2², 2⁴, 2⁸, 2¹⁶).

133. What comes next: 6, 36, 216, ?
A) 600
B) 1296
C) 1500
D) 2000
👉 Explanation: ×6 each time.

134. Series: 125, 25, 5, 1, ?
A) 0
B) 0.2
C) 0.5
D) 1.5
👉 Explanation: ÷5 each step.

135. Find missing: 2, 12, 72, 432, ?
A) 1000
B) 2592
C) 3000
D) 3600
👉 Explanation: ×6 each step.

136. Series: 7, 21, 63, 189, ?
A) 300
B) 567
C) 600
D) 700
👉 Explanation: ×3 pattern.

137. What comes next: 3, 12, 60, 360, ?
A) 1500
B) 2000
C) 2520
D) 3000
👉 Explanation: ×4, ×5, ×6, ×7.

138. Series: 19, 38, 57, 76, ?
A) 85
B) 95
C) 100
D) 105
👉 Explanation: +19 each step.

139. Find missing: 8, 16, 32, 64, ?
A) 90
B) 128
C) 150
D) 200
👉 Explanation: ×2 pattern.

140. Series: 100, 200, 400, 800, ?
A) 1200
B) 1600
C) 1800
D) 2000
👉 Explanation: ×2 each step.

141. Next number: 11, 121, 1331, ?
A) 12000
B) 12300
C) 14641
D) 15000
👉 Explanation: Powers of 11.

142. Series: 6, 11, 21, 36, ?
A) 46
B) 56
C) 66
D) 76
👉 Explanation: Differences = 5, 10, 15, 20…

143. Find missing: 3, 6, 18, 72, ?
A) 200
B) 360
C) 400
D) 450
👉 Explanation: ×2, ×3, ×4, ×5…

144. Series: 2, 5, 10, 17, 26, ?
A) 30
B) 35
C) 37
D) 40
👉 Explanation: +3, +5, +7, +9, +11.

145. Next number: 4, 16, 64, 256, ?
A) 500
B) 1024
C) 1500
D) 2000
👉 Explanation: Powers of 4.

146. Series: 7, 14, 28, 56, ?
A) 90
B) 100
C) 112
D) 120
👉 Explanation: ×2 pattern.

147. Find missing: 2, 8, 32, 128, ?
A) 200
B) 512
C) 600
D) 700
👉 Explanation: ×4 each step.

148. Series: 81, 243, 729, ?
A) 1500
B) 2187
C) 2500
D) 3000
👉 Explanation: Powers of 3.

149. What comes next: 1000, 100, 10, 1, ?
A) 0
B) 0.1
C) 0.5
D) 2
👉 Explanation: ÷10 each step.

150. Series: 2, 3, 5, 9, 17, ?
A) 25
B) 33
C) 35
D) 40
👉 Explanation: Double previous –1.