In
series completion some numbers, which are following some particular pattern are
given and we are ask to find the no missing in the given series.

Some
rules used in such problems are as follows:

**Rule-1**

Add
or subtract or multiply or divide by certain no in order to get next no.

*Example*: 8, 12, 16, ___, 24, 28.

*Explanation*: Here next no can be achieved by simply add

*4**to the previous no.Hence the missing no would be*

**20.**

**Rule-2**

Apply
the below given mathematical combinations in order to get the next no.

Addition & SubtractionMinus & MultiplicationMultiplication & DivisionDivision & Addition |

*Example:*15, 10, 5, 150, 16, 12, 4, 192, 20, 15, 5, ____

*Explanation:*Here the 3

^{rd}no can be achieved by subtracting the 2

^{nd}no from 1

^{st}while the 4

^{th}no is achieved by multiplying the 1

^{st}and 2

^{nd}and so on. Therefore the combination used here is

**Hence by this combination the missing no would be**

*Subtraction & multiplication.***300.**

**Rule-3**

Multiplication
of any number of series.

*Example*: 3, 10, 33, 104, _____

*Explanation*: Here the pattern followed is as per

3*3+1 =10

10*3+3 =33

33*3+5 =104

104*3+7
=319

**Rule-4**

Squares
(or) Cubes

*Example*: 2, 12, 56, 182, 462,____

*Explanation*:

2=1

^{2}+1
12= 3

^{2 }+3
56= 7

^{2}+7
182=13

^{2}+13
462=21

^{2}+ 21
The series formed by subtracting the
consecutive no after splitting into square form is

3-1=2

7-3=4

13-7=6

21-13=8

**X - 21**=

**10 ,**Thus

**X= 31**and hence the missing no=

**31**

^{2}+31= 992