Series completion is a very important and trickier topic of both verbal and non-verbal reasoning. There are numerous questions out of this section, which is not only asked in SSC exams but also in other competitive exams. There are nearly 1-2 questions are asked from series verbal reasoning in SSC Tier-1 exams.
Model Questions
Directions (Qs. 1 - 12): Select the number from among the given options that can replace the question mark (?) in the following series.
1. 1, 9, 25, 49, 81, ?
a) 64 b) 121 c) 91 d) 125
Sol: The pattern is 12, 32, 52, 72, 92, 112.
So the missing number is 121. Ans: b
2. 6, 12, ?, 33, 48
a) 21 b) 38 c) 40 d) 45
Sol: The pattern followed in the given series is
+6, +9, +12, +15, ......
So, missing number is 12 + 9 = 21.
Ans: a
3. 6, 11, 21, 36, ?, 81
a) 42 b) 61 c) 56 d) 91
Sol: The pattern followed in the given series is
+5, +10, +15, +20, +25, ........
So, ? = 36 + 20 = 56. Ans: c
4. 4, 10, 28, ?, 244, 730
a) 24 b) 82 c) 77 d) 218
Sol: The pattern is
4 × 3 − 2 = 10
10 × 3 − 2 = 28
28 × 3 − 2 = 82
So, the missing term is 82. Ans: b
5. 198, 194, 185, ?, 144
a) 92 b) 112 c) 136 d) 169
Sol: The pattern is
198 − 22 = 194
194 − 32 = 185
185 − 42 = 169
169 − 52 = 144 Ans: d
6. 2, 3, 8, ?, 112, 565
a) 226 b) 339 c) 452 d) 27
Sol: The pattern is
2 × 1 + 1 = 3
3 × 2 + 2 = 8
8 × 3 + 3 = 27
27 × 4 + 4 = 112
112 × 5 + 5 = 565. Ans: d
7. 10, 100, 200, ?, 430
a) 300 b) 410 c) 420 d) 310
Sol: This is an increasing series
10 + 90 = 100
100 + 100 = 200
200 + 110 = 310
310 + 120 = 430. Ans: d
8. 1, 5, 14, 30, ?, 91, 140
a) 60 b) 55 c) 65 d) 50
Sol: The pattern is
1 + 22 = 5
5 + 32 = 14
14 + 42 = 30
30 + 52 = 55
55 + 62 = 91
91 + 72 = 140. Ans: b
9. 1, 1, 2, 6, 24, 120, ?
a) 160 b) 540 c) 620 d) 720
Sol: The pattern is
1 × 1 = 1
1 × 2 = 2
2 × 3 = 6
6 × 4 = 24
24 × 5 = 120
120 × 6 = 720. Ans: d
10. 240, ?, 120, 40, 10, 2.
a) 180 b) 240 c) 420 d) 480
Sol: The pattern is
240 ÷ 1 = 240
240 ÷ 2 = 120
120 ÷ 3 = 40
40 ÷ 4 = 10
10 ÷ 5 = 2 Ans: b
11. 4, 12, 36, ?, 324
a) 144 b) 216 c) 72 d) 108
Sol: These numbers are in geometric progression.
4 × 3 = 12
12 × 3 = 36
36 × 3 = 108
108 × 3 = 324 Ans: d
12. 6, 17, 39, ?, 116
a) 83 b) 94 c) 116 d) 127
Sol: The pattern is
6 + 11 = 17
17 + 22 = 39
39 + 33 = 72
72 + 44 = 116 Ans: c
Directions (Qs. 13 - 27): Choose the missing term out of given alternatives.
13. 24, 35, 51, 73, 102, ?
[SSC-CGL 2020]
a) 139 b) 151 c) 131 d) 149
Sol:
14. PNNA, RPPE, TRRI, VTTO, ?
a) YVVU b) XWWU c) XVVU d) YUUV
Sol: Take the first set of letters
15. 4, 11, 31, 65, ?, 389
a) 71 b) 198 c) 277 d) 193
Sol: The pattern is
4 × 2 + 3 = 11
11 × 3 - 2 = 31
31 × 2 + 3 = 65
65 × 3 - 2 = 193
193 × 2 + 3 = 389 Ans: d
16. 27, 30, 37, 50, ?, 98
[SSC-CGL 2020]
a) 82 b) 69 c) 62 d) 78
Sol: Alternate prime numbers are added in the
sequence to get the next term in the series.
18. CMQR, BONV, AQKZ, ZSHD, ?
[SSC-CGL 2020]
a) ZVGH b) YUEH c) YUEI d) ZUGH
Sol: According to position of letters.