Series Completion: General Intelligence or Reasoning MCQ Question with Answer This chapter deals with questions in which series of numbers or alphabetical letters are given, which are generally called as terms of the series. These terms follow a certain pattern throughout. The candidate is required to recognize this pattern and either complete the given series with the most suitable alternative or find the wrong term in the series.
Quiz-1 Quiz-2 Quiz-3 Quiz-4 Quiz-5
Direction: What should come in place of question mark (?) in the following number series?
Q1. 24, 21, 18, ?, 12, 9
(a) 10
(b) 15
(c) 14
(d) 16
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Answer: (b)Explanation: 24 – 21 = 21 – 18 = 18 – ? = ? – 12 = 12 – 9 = 3
or ? = 15
Q2. 7, 12, 19, ?, 39
(a) 24
(b) 26
(c) 28
(d) 30
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Answer: (c)Explanation: The given sequence follows the pattern : + 5, +7, +9 … i.e., 7 + 5 = 12, 12 + 7=19
∴ Missing number = 19 + 9 = 28.
Q3. 2, 4, 8, 14, 22, 32, ?
(a) 40
(c) 42
(c) 44
(d) 46
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Answer: (c)Explanation: The given sequence follows the pattern : +2, +4, +6, +8, +10, +12 … i.e., 2+2 =4, 4+4=8, 8+6=14, 14+8=22, 22+10 = 32,
∴ Missing number = 32+12=44.
Q4. 0, 6, 24, 60, 120, 210 ?
(a) 250
(b) 290
(c) 325
(d) 336
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Answer: (d)Explanation: the given series is 13 – 1, 23 – 2, 33 – 3, 43 – 4. 53 – 5. 63 –6,
∴ Next number = 73 – 7 = 343 – 7 = 336.
Q5. 4, 6. 12, 14, 28, 30, ( ?)
(a) 32
(b) 60
(c) 62
(d) 64
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Answer: (b)Solution: The given sequence is a combination of two series :
I ⇒ 4. 12, 28, ( ) and II⇒ 6. 14, 30.
Now, the pattern followed in each of the above two series is : + 8, + 16. + 32
So. missing number = (28 + 32) = 60.
Q6. 3, 4, 6, 9, 13, 18, ?
(a) 22
(b) 24
(c) 26
(d) 28
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Answer: (b)Explanation: The given series is +1, +2, +3, +4, +5, +6
∴ Next number = 18 + 6 = 24
Q7. 6174, 882, 126, ?
(a) 18
(b) 20
(c) 24
(d) 30
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Answer: (a)Explanation: Series is divide by 7.
∴ Next number = 126/7 = 18
Q8. 1. 3, 3, 6, 7, 9, ?, 12, 21.
(a) 10
(b) 11
(c) 12
(d) 13
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Answer: (d)Explanation: Clearly, the given sequence is a combination of two series :
I → 1, 3, 7, ?, 21 and II → 3, 6, 9, 12
The pattern followed in I is + 2. + 4, +6, +8 .; and the pattern followed in II is + 3, +3, +3
∴ missing number = 7 + 6 = 13.
Q9. In the series 357, 363, 369, …. what will be the 10th term ?
(a) 405
(b) 411
(c) 413
(d) 417
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Answer: (b)Explanation: The given series is an A.P. in which First Term (a) = 357 and Common difference (d) = 6.
10th term = a (10 – 1)d = a + 9d = (357 + 9 x 6) = (357 + 54) = 411.
Q10. 1, 4, 9. 16, 25, (? )
(a) 35
(b) 36
(c) 48
(d) 49
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Answer: (b)Explanation: the given series is 12 , 22 , 32 , 42 , ….
∴ missing number = 62
