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That follow a logical rule..!
NUMBER SERIES
Series is divided into two types. One is Number series and another one is Letter series. In Bank clerk exams 5 questions are covering from number series.
Number series tests present numerical sequences that follow a logical rule which is based on elementary arithmetic. An initial sequence is given from which the rule is to be deduced. You are then asked to predict the next number that obeys the rule.
Practice Questions
Directions(1-5): What should come in place of question mark (?) in the following number series.
(SBI Clerk 6-1-2008)
1. 12, 6.5, 7.5, 12.75, 27.5, 71.25, ?
1) 225.75 2) 216.75
3) 209.75 4) 236.75
5) 249.75
2. 16, 24, 36, 54, 81, 121.5, ?
1) 182.25 2) 174.85
3) 190.65 4) 166.55
5) 158.95
3. 12, 12, 18, 45, 180, 1170, ?
1) 13485 2) 14675
3) 15890 4) 16756
5) 12285
4. 22, 23, 27, 36, 52, 77, ?
1) 111 2) 109
3) 113 4) 117
5) 115
5. 16, 14, 24, 66, 256, 1270, ?
1) 8564 2) 5672
3) 4561 4) 7608
5) 6340
Directions (6-10) In the following number series, a wrong number is given. Find out that wrong number.
(SBI Clerk 10-2-2008)
6. 2, 11, 38, 197, 1172, 8227, 65806
1) 11 2) 38
3) 197 4) 1172
5) 8227
7. 16, 19, 21, 30, 46, 71, 107
1) 19 2) 21
3) 30 4) 46
5) 71
8. 7, 9, 16, 25, 41, 68, 107, 173
1) 107 2) 16
3) 41 4) 68
5) 25
9. 4, 2, 3.5, 7.5, 26.25, 118.125
1) 118.125 2) 26.25
3) 3.5 4) 2
5) 7.5
10. 16, 4, 2, 1.5, 1.75, 1.875
1) 1.875 2) 1.75
3) 1.5 4) 2 5) 4
Directions (11-13): What will come in place of the question mark (?) in the following number series?
(Union Bank of India 6-2-2011)
11. 17, 98, 147, 172, 181, ?
1) 180 2) 192
3) 184 4) 182
5) None of these
12. 11, 19, 31, 47, 67, ?
1) 80 2) 81
3) 86 4) 96
5) None of these
13. 748, 460, 316, 244, 208, ?
1) 180 2) 190
3) 172 4) 182
5) None of these
Directions (14-16): What will come in place of the question mark (?) in the following number series.
14. 12, 16, 24, 36, 52, ?
1) 80 2) 76
3) 72 4) 82
5) None of these
15. 17, 21, 37, 73, 137, ?
1) 246 2) 236
3) 217 4) 237
5) None of these
16. 620, 412, 308, 256, 230, ?
1) 217 2) 227
3) 207 4) 234
5) None of these
Directions (17-18): What will come in place of the question mark (?) in the following number series.
(Bank of Baroda 6-6-2010)
17. 153, 150, 144, 132, 108, ?
1) 60 2) 84
3) 54 4) 72
5) None of these
18. 31, 40, 58, 85, 121, ?
1) 166 2) 175
3) 157 4) 184
5) None of these
Directions (19-23): What should come in place of the question mark (?) in the following number series?
19. 36, 37, 46, 71, ? 201, 322
1) 120 2) 107
3) 135 4) 96
5) None of these
20. 12, 20, 100, ? 8900, 88900, 888900
1) 1000 2) 900
3) 800 4) 500
5) None of these
21. 7, 7, 14, 42, 168, ?, 5040
1) 672 2) 850
3) 740 4) 800 5) None of these
22. 21, 30, 12, 39, 3, ?, -6
1) 66 2) 12
3) 48 4) 75
5) None of these
23. 10, 24, 52, ?, 220, 444, 892
1) 104 2) 98 3) 112 4) 108 5) None of these
Solutions
4. Ans: 3
Here given number series is based on the following pattern
22 + 12 = 22 + 1 = 23
23 + 22 = 23 + 4 = 27
27 + 32 = 27 + 9 = 36
36 + 42 = 36 + 16 = 52
52 + 52 = 52 + 25 = 77 and
77 + 62 = 77 + 36 = 113
5. Ans: 4
The given number series is based on the following pattern
16 ´ 1 – 2 = 14
14 ´ 2 – 4 = 24
24 ´ 3 – 6 = 66
66 ´ 4 – 8 = 256
256 ´ 5 – 10 = 1270 and
1270 ´ 6 – 12 = 7608
6. Ans: 4
The series is based on the following pattern
2 ´ 3 + 5 = 11
11 ´ 4 – 6 = 38
38 ´ 5 + 7 = 197
197 ´ 6– 8 = 1174 : it is not 1172
1174 ´ 7 + 9 = 8227
8227 ´ 8 ´ 10 = 65806
Clearly 1172 is the wrong number and it should be replaced by 1174
7. Ans: 1
The series is based on the following pattern
16 + 12 = 17 but not 19
17 + 22 = 21
21 + 32 = 30
30 + 42 = 46
46 + 52 = 71
71 + 62 = 107
Clearly 19 should be replaced by 17
8. Ans: 4
The series is based on the following pattern.
7 + 9 = 16
9 + 16 = 25
25 + 41 = 66 but not 68
41 + 66 = 107
66 + 107 = 173
So 68 should be replaced by 66
9. Ans: 3
The series is based on the following pattern
4 ´ 0.5 = 2
2 ´ 1.5 = 3 but not 3.5
3 ´ 2.5 = 7.5
7.5 ´ 3.5 = 26.25
26.25 ´ 4.5 = 118.25
So 3.5 should be replaced with 3
10. Ans: 2
The series is based on the following pattern.
16 ´ 0.25 = 4
4 ´ 0.5 = 2
2 ´ 0.75 = 1.5
1.5 ´ 1.00 = 1.5 but not 1.75
1.5 ´ 1.25 = 1.875
So 1.75 should be replaced by 1.5
11. Ans: 4
The series is based on the following pattern.
17 + 92 = 98
98 + 72 = 147
147 + 52 = 172
172 + 32 = 181
181 + 12 = 182
So the ans is 182
12. Ans: 5
The series is based on the following pattern.
11 + 8 = 19
19 + 12 = 31
31 + 16 = 47
47 + 20 = 67
67 + 24 = 91
So the ans is 91
13. Ans: 2
The series is based on the following pattern.
748 – 288 = 460
460 – 144 = 316
316 – 72 = 244
244 – 36 = 208
208 – 18 = 190
14. Ans: 3
The series is based on the following pattern.
12 + 4 = 16
16 + 8 = 24
24 + 12 = 36
36 + 16 = 52 and
52 + 20 = 72
15. Ans: 4
The series is based on the following pattern.
17 + 22 = 21
21 + 42 = 37
37 + 62 = 73
73 + 82 = 137 and
137 + 102 = 237
16. Ans: 1
The series is based on the following pattern.
620 – 208 = 412
412 – 104 = 308
308 – 52 = 256
256 – 26 = 230 and
230 – 13 = 217
17. Ans: 1
The series is based on the following pattern.
153 – 3 = 150
150 – 6 = 144
144 – 12 = 132
132 – 24 = 108
108 – 48 = 60
So the ans is 60
18. Ans: 1
The series is based on the following pattern.
31 + 9 = 40; 40 + 18 = 58
58 + 27 = 85; 85 + 36 = 121
121 + 45 = 166
19. Ans: 1
The series is based on the following pattern.
36 + 12 = 37
37 + 32 = 46
46 + 52 = 71
71 + 72 = 120
120 + 92 = 201
201 + 112 = 322
So the ans is 120
20. Ans: 2
The series is based on the following pattern.
12 + 8 = 20
20 + 80 = 100
100 + 800 = 900
900 + 8000 = 8900
8900 + 80000 = 88900
88900 + 800000 = 888900
21. Ans: 5
The series is based on the following pattern.
7 ´ 1 = 7; 7 ´ 2 = 14
14 ´ 3 = 42; 42 ´ 4 = 168
168 ´ 5 = 840; 840 ´ 6 =5040
22. Ans: 3
The series is based on the following pattern.
21 + 9 = 30; 30 – 18 = 12
12 + 27 = 39
39 – 36 = 3
3 + 45 = 48
48 – 54 = –6
