Series Completion - Section 2
Choose the correct alternative that will
continue the same pattern and replace the question mark in the given series.
1. 1, 1,
2, 6, 24, ?, 720
A.100
B.104
C.108
D.120
Answer: Option-D
Explanation:
The
pattern is x 1, x 2, x 3, x 4,…..
So,
missing term = 24 x 5 = 120.
2. 2, 15,
4, 12, 6, 7, ?, ?
A.8, 8
B.8, 0
C.3, 8
D.None of
these
Answer: Option-B
Explanation:
Let the
missing terms of the series be x1 and x2.
Thus, the
sequence 2, 15, 4, 12, 6, 7, x1 x2 is a combination of two series :
I. 2, 4,
6, x1 and II. 15, 12, 7, x2I consists of consecutive even
numbers.
So,
missing term, x1 = 8.
The
pattern in II is - 3, - 5,......So, missing term, x2 = 7 - 7 = 0.
3. 4832,
5840, 6848, ?
A.7815
B.7846
C.7856
D.7887
Answer: Option-C
Explanation:The
pattern is + 1008.
So,
missing term - 6848 + 1008 = 7856.
4. 5824,
5242, ?, 4247, 3823
A.4467
B.4718
C.4856
D.5164
Answer: Option-B
Explanation:Each term
in the series is obtained by subtracting from the preceding term the number
formed by
the first three digits of the preceding term.
So, missing term = 5242 - 524 =
4718.
5. 2, 8,
16, 128, ?
A.2042
B.2046
C.2048
D.2056
Answer: Option-C
Explanation: Each term
in the series, except the first two terms, is the product of the preceding two
terms.
So, missing term = 16 x 128 =
2048.
6. 1, 2,
6, 7, 21, 22, 66, 67, ?
A.70
B.134
C.201
D.301
Answer: Option-C
Explanation:
The pattern is + 1, x 3, + 1, x 3, + 1, x 3, +
1,.....
So, missing term = 67 x 3 = 201.
7. 0.5, 0.55, 0.65,0.8,?
A.0.9
B.0.82
C.1
B.0.95
Answer: Option-C
Explanation:
The pattern is + 0.05, + 0.10, + 0.15,.....
So, missing term = 0.8 + 0.20 = 1.
8. 0, 2, 3, 5, 8, 10, 15, 17, 24,
26, ?
A.28
B.30
C.32
D.35
Answer: Option-D
Explanation:The given
sequence is a combination of two series :
I. 0, 3, 8, 15, 24, ? and II. 2, 5, 10, 17, 26
The pattern in each one of I and II is + 3, + 5, +
7, + 9, .....
So, missing term = 24 + 11 = 35.
9. 11, 13, 17, 19, 23, 25, ?
A.26
B.27
C.29
D.37
Answer: Option-C
Explanation: The pattern
is + 2, + 4, + 2, + 4, …..
So, missing term = 25 + 4 = 29.
10. 5, 2, 7, 9, 16, 25, ?
A.41
B.45
C.48
D.52
Answer: Option-A
Explanation:Each term
in the series, except the first two terms, is the sum of the preceding two
terms.
So, missing term = 16 + 25 = 41.
11. 7,
26, 63, 124, 215, 342, ?
A.391
B.421
C.481
D.511
Answer: Option-D
Explanation:The terms
of the given series are (23 -
1), (33 - 1), (43 - 1), (53 - 1), (63 - 1), (73 - 1),.....
So, missing term = (83 - 1) = (512 - 1) = 511.
12. 3, 12,27,48, 75, 108,?
A.147
B.162
C.183
D.192
Answer: Option-A
Explanation:The terms
of the given series are 3 x l2, 3 x 22, 3 x 32, 3 x 42, 3 x 52, 3 x 62,.....
So, missing term = 3 x 72 = 3 x 49 = 147.
13. 3, 7, 23, 95, ?
A.62
B.128
C.479
D.575
Answer: Option-C
Explanation:The
pattern is x 2 + 1, x 3 + 2, x 4 + 3,.....
So, missing term = 95 x 5 + 4 = 479.
14. 6, 18, 3, 21, 7, 56, ?
A.8
B.9
C.63
D.64
Answer: Option-A
Explanation: Each term
at an even place in the series is the product of its two adjacent terms.
Thus, if the missing term be x, then we have : 7 x
x = 56 or x = 56 ÷ 7 = 8.
15. 4, 9, 25, ?, 121, 169, 289,
361
A.49
B.64
C.81
D.87
Answer: Option-A
Explanation: The given
series consists of squares of consecutive prime numbers
i.e. 22, 32, 52,.....,
112, 132, 172, 192.
So, missing term = 72 = 49.
16. 6,
13,28,59,?
A.111
B.113
C.114
D.122
Answer: Option-D
Explanation:
The pattern is x 2 + 1, x 2 + 2, x 2 + 3,.....
So, missing term = 59 x 2 + 4 = 122.
17. 4, 12, 36, 108, ?
A.144
B.216
C.304
D.324
Answer: Option-D
Explanation:
The pattern is x 3.
So, missing term = 108 x 3 = 324.
18. Which term of the series 5,
8, 11, 14,.....is 320 ?
A.104th
B.105th
C.106th
D.64th
Answer: Option-C
Explanation: Clearly,
5 + 3 = 8, 8 + 3 = 11, 11 + 3 = 14, .....
So, the series is an A.P. in which a - 5 and d = 3.
Let 320 be the nth term of the series.
Then, 320 = 5 + (n - 1) x 3 or (n - 1) = 105 or n =
106.
19. 8, 9, 8, 7, 10, 9, 6, 11, 10,
?, 12
A.5
B.7
C.8
D.11
Answer: Option-A
Explanation:
The given sequence is a combination of three series
:
I. 1st, 4th, 7th, 10th terms i.e. 8, 7, 6, ?
II. 2nd, 5th, 8th, 11th terms i.e. 9, 10, 11, 12
III. 3rd, 6th, 9th terms i.e. 8, 9, 10 The pattern
in I is - 1.
So, missing term = 6 - 1 = 5.
20. 3, 7, 15, ?, 63, 127
A.30
B.31
C.47
D.52
Answer: Option-B
Explanation:
Each number in the series is one more than twice
the preceding number.
So, missing term = (15 x 2) + 1 = 31.
21. 4,
10, ?, 82, 244, 730
A.24
B.28
C.77
D.218
Answer: Option-B
Explanation: Each
number in the series is 2 less than thrice the preceding number.
So, missing number = (10 x 3) - 2 = 28.
22. 1, 5, 13,25,41,?
A.51
B.57
C.61
D.63
Answer: Option-C
Explanation:The
pattern is + 4, + 8, + 12, + 16......
So, missing term = 41 + 20 = 61.
23. 325, 259, 204, 160, 127, 105,
?
A.94
B.96
C.98
D.100
Answer: Option-A
Explanation:
The pattern is - 66, - 55, - 44, - 33, - 22, .....
So, missing term = 105 - 11 = 94.
24. 4, 7, 12, 19, 28, ?
A.30
B.36
C.39
D.49
Answer: Option-C
Explanation:
The pattern is + 3, + 5, + 7, + 9, .....
So, missing term = 28 + 11 = 39.
25. 5760, 960, ?, 48, 16, 8
A.120
B.160
C.192
D.240
Answer: Option-C
Explanation:The
pattern is ÷ 6, ÷ 5, ÷ 4, ÷ 3, ÷ 2.
So, missing term = 960 - 5 = 192.
26. 45,
54, 47, ?, 49, 56, 51, 57, 53
A.48
B.50
C55
D.None of
these
Answer: Option-C
Explanation:The given
sequence is a combination of two series:
I. 45, 47, 49, 51, 53 and II. 54, ?, 56, 57
Clearly, II consists of consecutive natural
numbers, starting from 54.
So, missing term = 55.
27. 3, 8, 13, 24, 41, ?
A.70
B.75
C.80
D.85
Answer: Option-A
Explanation:The
pattern followed is : nth term + (n + l)th term + (n + 1) = (n + 2)th term.
Thus, 1st term + 2nd term + 2 = 3rd term; 2nd term
+ 3rd term + 3 = 4th term and so on.
So, missing term = 6th term = 4th term + 5th term +
5 = 24 + 41 + 5 = 70.
28. 10, 14, 26, 42, 70, ?
A.100
B.102
C.106
D.114
Answer: Option-D
Explanation:Each term
in the series, except the first two terms, is 2 more than the sum of the
preceding two terms.
So, missing term = (42 + 70) + 2 = 114.
29. 10, 18, 28, 40, 54, 70, ?
A.85
B.86
C.87
D.88
Answer: Option-D
Explanation:The pattern
is + 8, + 10, + 12, + 14, .....
So, missing term = 70 + 18 = 88.
30. 8, 28, 116, 584, ?
A.1752
B.3502
C.3504
D.3508
Answer: Option-D
Explanation:The
pattern is x 3 + 4, x 4 + 4, x 5 + 4,.....
So, missing term = 584 x 6 + 4 = 3508.