# Series - How to Find Missing Number

Series Is a set or sequence of elements which may be numbers, letters, symbols etc… which either follow a particular pattern or has an internal logic between them. In general Number series and letter, series are asked in the exam.

Again in the number and letter series, there are
• MISSING NUMBER/LETTER SERIES
• WRONG NUMBER/LETTER SERIES

Let us first discuss regarding number series. For some aspirants, number series is an easy and scoring topic but for some aspirants, it is t, e most difficult thing, Some can identify the logic between the numbers easily but for some, it is like is an irritating thing. As a set of 5 questions are asked in the exam we cannot afford to leave this topic. So for this regular practice is the key to success for this topic. First, let us divide the number series into following categories…
• Number based series
• Subtraction based series
• Multiplication based series
• Division based series
• Miscellaneous series

Practice this topic in an above-said manner. First, try the question whether it is a number based or Addition or difference based series then move on to the different categories.
To crack the series topic one should be perfect with Prime numbers, squares, cubes, squares of prime numbers, cubes of prime numbers.

SQUARES
1 1 26 676
2 4 27 729
3 9 28 784
4 16 29 841
5 25 30 900
6 36 31 961
7 49 32 1024
8 64 33 1089
9 81 34 1156
10 100 35 1225
11 121 36 1296
12 144 37 1369
13 169 38 1444
14 196 39 1521
15 225 40 1600
16 256 41 1681
17 289 42 1764
18 324 43 1849
19 361 44 1936
20 400 45 2025
21 441 46 2116
22 484 47 2209
23 529 48 2304
24 576 49 2401
25 625 50 2500

CUBES
1 1 8 512
2 8 9 729
3 27 10 1000
4 64 11 1331
5 125 12 1728
6 216 13 2197
7 343 14 2744
15 3375

Number(N) N2 N3 N2 +1 N2-1 N3-1 N3+1 Nn Nn +1 Nn/2 N3+N N3-N
0 0 1
1 1 2
2 4 9
3 3 28
4 16 65
5 25 126
6 36 217
7 49 344
8 64 513
9 81 730
10 100 1001
By remembering the vertical rows of the above table, aspirants would be benefited in identifying the difference pattern among the numbers. Now let us discuss some questions.

### Question 15.  17, 98, 26, 89, 35, -------- ( IBPS PO PRLIMS-2017)

Smart Prep Kit for Banking Exams by Ramandeep Singh - Download here