Number series are very important topic for BANK EXAMS (SBI, IBPS & RRB).
Number series are very important topic for BANK EXAMS (SBI, IBPS & RRB). 



What is Number Series?
No. Series is an arrangement of numbers in a certain way, where some numbers are missing in series or some numbers are mistakenly put into number series. In Bank PO competitive exams you need to find missing number or find out the mistakenly put number into the number series. The number series can come in various types, at first you have to decide which type of number series is given in exam then you should use various Number series shortcut tricks to solve the number series problem as soon as possible. Below we are going to explain various shortcut methods for Number series problems.


Different types of Number Series

 There are various types of number series which are given in exams.

Square series: These are also known as perfect square series which are based on square of a number in same order. In exam it can be missing square or mistakenly put square in series.

Example:  289, 324, 361, 400, ?'
Answer: 289 = 172, 324 = 182, 361 = 192, 400 = 202, 441 = 212
Cube series: These type of series based on perfect cube. In exam there can be missing cube or mistakenly put cube in number series.
Example: 1728, 2197, 2744, 3375, ?
Answer: 1728 = 123, 2197 = 133, 2744 = 143, 3375 = 153, 4096 = 163
Geometric Series: It is the sequence of numbers based on ascending or descending order. Next number is obtaining by multiplying or dividing the previous number or vice versa.
Example: 9, 54, 324, 1944, ?
Answer: 9 x 6 = 54, 54 x 6 = 324, 324 x 6 = 1944, 1944 x 6 = 11664


Mixed Series: This type of number series can be used various method. In this number may be given in addition, subtraction, multiplication and division in the alternate numbers. It is created according to any non-conventional rule.
Example: 10, 31, 94, 283, ?
Answer: 10 x 3 = 30 + 1 = 31,
                31 x 3 = 93 + 1 = 94,
                94 x 3 = 282 + 1= 283,
                283 x 3 = 849 + 1 = 850,
So the missing number is 850.

Number Series Quiz
Directions (1-10): What should come in place of the question marks (?) in the following Number Series:
1.      104, 109, 99, 114, 94, ?
a.      69
b.      124
c.       120
d.      119
e.      None of these

2.      14, 16, 35, 109, 441, ?
a.      2651
b.      2205
c.       2315
d.      2211
e.      None of these

3.      4, 6, 10, 16, 26, ?
a.      24
b.      42
c.       36
d.      61
e.      None of these

4.      3, 8, 18, 33, 53, ?
 a.      78
 b.      87
c.       63
d.      56
e.      None of these
       5.      81, 100, 121, 144, 169, ?
       a.      198
b.      196
c.       224
d.      145
e.      None of these

Answers with explanation:
Answer 1. (D)
The pattern is +5, -10, +15, -20, +25
So the missing term is 119

Answer 2. (D)
The pattern is   x1+2, x2+3, x3+4, x4+5, x5+6 
So the missing term is 2211

Answer 3. (B)
he pattern is 4+6=10, 10+16=26, 26+16=42 
So the missing term is 42

Answer 4. (A)
The pattern is 
Here the difference between two consecutive numbers is

·         8 - 3 =  5
·         18 - 8 = 10
·         33 - 18 = 15
·         53 - 33 = 20
·         78 - 53 = 25
Difference is increased by multiple by 5. So the answer is 78.

Answer 5. (B)
The pattern is 81 = 92, 100 = 102, 121 = 112, 144 = 122, 169 = 132, 196 = 142
so the missing term is 196.

THANK YOU 
BEST OF LUCK FOR EXAM