Hard Number Series Questions Solution Competitive Exams Set 8

Advanced 467 Reasoning Puzzles Book SBI PO 2018

Number Series Questions For IBPS PO SBI SSC

Nowadays, almost in all competitive exams  Number Series related questions is must ask and especially in Bank Recruitment Exams.

Most Bank PO Exams including IBPS PO, SBI PO, and other exams ask 5-10 questions from Number Series. It is very important to practice difficult number series questions, as they can generally be solved in short span of time with high accuracy. Today, we have 20 difficult number series questions to help you practice Number Series. As usual, answers and solution are following the questions.


Following are some  Number Series questions which are likely to be asked/ already asked in competitive exams. Following  Number Series questions will help you securing good marks in upcoming SBI PO, SBI Clerk, IBPS PO­, IBPS Clerk­, IBPS RRB Exams in 2017 2018.

Number Series Questions with Solutions pdf

Directions (1 - 5): In the following number series, a wrong number is given. Find out that wrong number.

1. 2 11 38 197 1172 8227 65806
(1) 11 
(2) 38
(3) 197 
(4) 1172
(5) 8227

2. 16 19 21 30 46 71 107
(1) 19
(2) 21
(3) 30 
(4) 46
(5) 71

3. 7 9 16 25 41 68 107 173
(1) 107 
(2) 16
(3) 41 
(4) 68
(5) 25

4. 4 2 3.5 7.5 26.25 118.125
(1) 118.125
(2) 26.25
(3) 3.5 
(4) 2
(5) 7.5

5. 16 4 2 1.5 1.75 1.875
(1) 1.875 
(2) 1.75
(3) 1.5 
(4) 2
(5) 4

Directions (6 - 10): What will come in place of the question mark (?) in the following number series?

6. 3 10 32 100 ?
(1) 345
(2) 460
(3) 308 
(4) 440
(5) None of these

7. 5 3 4 ? 38
(1) 8.5 
(2) 6
(3) 7.5 
(4) 8
(5) None of these

8. 5 6 ? 57 244
(1) 21 
(2) 16
(3) 17 
(4) 15
(5) None of these

9. 3 10 21 ? 51
(1) 34 
(2) 32
(3) 33 
(4) 37
(5) None of these

10. 5 11 ? 55 117
(1) 21 
(2) 27
(3) 23 
(4) 25
(5) None of these

Directions (11 - 15): In each of the following questions a number series is given. After the series, a number is given followed by (a), (b), (c), (d) and (e). You have to complete the series starting with the number given, following the sequence of the original series and answer the questions that follow the series.

11. 12   30   120   460   1368   2730
      16   (a)   (b)    (c)     (d)       (e)
What will come in place of (d) ?
(1) 1384 
(2) 2642
(3) 2808 
(4) 1988
(5) None of these

12. 154   462   231   693   346.5   1039.5
      276    (a)    (b)    (c)     (d)         (e)
What will come in place of (e) ?
(1) 1746 
(2) 621
(3) 1242 
(4) 983
(5) None of these

13. 7        91   1001   7007   35035   105
     14.5   (a)     (b)       (c)       (d)       (e)
What will come in place of (c) ?
(1) 21132.5 
(2) 14514.5
(3) 20020.5 
(4) 13864.5
(5) None of these

14. 582   574   601   537   662   446
      204   (a)     (b)     (c)    (d)    (e)
What will come in place of (d) ?
(1) 284 
(2) 68
(3) 174 
(4) 331
(5) None of these

15. 85   43    44   67.5   137   345
     125  (a)   (b)   (c)      (d)    (e)
What will come in place of (c) ?
(1) 86 
(2) 107.5
(3) 112.5 
(4) 97.5
(5) None of these

Directions (16 - 22) : What will come in place of the question mark (?) in the following number series?

16. 1 ? 27 64 125
(1) 8 
(2) 4
(3) 6 
(4) 9
(5) None of these

17. 25 16 ? 4 1
(1) 3 
(2) 6
(3) 12 
(4) 18
(5) None of these

18. 1 6 36 240 1960 ?
(1) 19660 
(2) 3680
(3) 36800 
(4) 19600
(5) None of these

19. 12 14 17 13 8 14 21 13 4 ?
(1) 14 
Number Series Questions Answers IBPS SBI SSC UPSC RRB(2) 13
(3) 15 
(4) 2
(5) None of these

20. 2 5 7 12 19 31 50 ?
(1) 53 
(2) 81
(3) 69 
(4) 74

Solution Answer Number Series Questions 

1. (4) The series is based on the following pattern:
11 = 2 × 3 + 5
38 = 11 × 4 - 6
197 = 38 × 5 + 7
1172 ≠ 197 × 6 - 8
Hence 1172 is wrong and it should be replaced by 197 × 6 - 8 = 1174

2. (1) The series is based on the following pattern:
107 - 71 = 36 = 6²
71 - 46 = 25 = 5²
46 - 30 = 16 = 
30 - 21 = 9 = 
21 - 19 = 2 ≠ 
Hence 19 should be replaced by 17 for which 21 - 17 = 

3. (4) The series is based on the following pattern:
16 = 9 + 7
25 = 16 + 9
41 = 25 + 16
68 ≠ 41 + 25

4. (3) The series is based on the following pattern:
Hard Number Series Questions

Obviously, 3.5 Is the wrong number which should be replaced by 3.

5. (2) The series is based on the following pattern:
Hard Number Series Questions For Bank PO Exams
Obviously, 1.75 is the wrong number which should be replaced by 1.5.

6. (3) The given series is based on the following pattern:
Hard Number Series Questions
Hence, 308 will come in place of the question mark.

7. (5) The given series is based on the following pattern:
Hard Number Series Questions
Hence, 10 will come in place of question mark.

8. (2) The given series is based on the following pattern:
5 × 1 + (1)² = 6
6 × 2 + (2)² = 16
16 × 3 + (3)² = 57
57 × 4 + (4)² = 244
Hence, 16 will come in place of question mark.

9. (1) The given series is based on the following patterns.
Hard Number Series Questions

Hence, 34 will come in place of the question mark.

10. (4) The given series is based on the following pattern:
5 × 2 + 1 = 11
11 × 2 + 3 = 25
25 × 2 + 5 = 55
55 × 2 + 7 = 117

11. (3) The given series is based on the following pattern:
30 = 12 × 6 - 7 × 6
120 = 30 × 5 - 6 × 5
460 = 120 × 4 - 5 × 4
1368 = 460 × 3 - 4 × 3
2730 = 1368 × 2 - 3 × 2
Similarly,
(a) = 16 × 6 - 7 × 6 = 96 - 42 = 54
(b) = 54 × 5 - 6 × 5 = 240
(c) = 240 × 4 - 5 × 4 = 940
(d) = 940 × 3 - 4 × 3 = 2808
Hence, 2808 will come in place of (d).

12. (5) The given series is based on the following pattern:
Hard Number Series Questions
Hence, 1863 will come in place of (e).

13. (2) The given series is based on the following pattern:
Hard Number Series Questions
Hence, 14514.5 will come in place of (c).

14. (1) The given series is based on the following pattern :
Hard Number Series Questions
Hence, 284 will come in place of(d).

15. (4) The given series is based on the following pattern:
Hard Number Series Questions
Hence, 97.5 will come in place of (c).

16. (1) The given series is based on the following pattern :

1 = 13
? = 23 = 8
27 = 33 
64 = 43
125 = 53
Hence, 8 will come in place of the question mark.

17. (5) The given series is based on the following pattern :
25 = 5² 
16 = 4²
? = 3² = 9 
4 = 2² and
1 = 1²
Hence, 9 will come in place of the question mark,

18. (1) The given series Is based on the following pattern:

1 × 2 + 2 × 2 = 6
6 × 4 + 4 × 3 = 36
36 × 6 + 6 × 4 = 240
240 × 8 + 8 × 5 = 1960
1960 × 10 + 10 × 6 = 19660
Hence, 19660 will come in place of the question mark.

19. (1) The given series is based on the following pattern :
Hard Number Series Questions
Hence, 14 will come in place of the question mark.

20. (2) The given series is based on the following pattern :

2 + 5 = 7 
7 + 5 = 12
12 + 7 = 19 
19 + 12 = 31
31 + 19 = 50 
50 + 31 = 81
Hence, 81 will come in place of the question mark.