Number Series Shortcut Tricks

Thursday, September 8, 2016

Number Series Shortcut Tricks

Number Series shortcut tricks for bank exams & competitive examinations. Number Series Formulas Important, Logical Reasoning Number Series questions and answers for Bank Exams, IBPS, UPSC, SSC and other competitive examinations. Number Series Shortcut Methods to solve Aptitude Questions fast and easily.

What is Number Series?

A series is an informally speaking of numbers. it is the sum of the terms of a sequence. Finite terms and series are defined by first and last terms while infinite series is endless. Number series is a form of series in which particular numbers are present in a particular order and missing numbers are to find out, nowadays number series is an important part of each and every government exams, especially in banks. It acquires a high weight.

A series is solved by particular number series tricks, formulas, attitudes of a person. There are various types of series present in the exam. Series can be of many types of Numbers like Natural numbers, Whole numbers, Contagious numbers etc. A sequence is described as a list of elements with a particular order.

Number Series can be made :-

Pure Series
Difference Series
Ratio Series
Mixed Series
Geometric Series
Two Tier Arithmetic Series
Other Type

1. Pure Series

In this type of number series, the number itself obeys certain order so that the character of the series can be found out.

The number itself may be.

Perfect Square

Example :

121, 144, 169, 225 ?

Answer - 256

Perfect Cube

Example :

6859, 5832, 4913, 4096, 3375, ?

Answer - 2744

2. Difference Series

Example :

1348, 1338, 1318, 1288, 1248, ?

Answer - 1198

3. Ratio Series

Example :

336, 168, 84, 42, 21, ?

Answer - 10.5

4. Mixed Series
Example :

222, 441, 1321, 2639, 7915, ?

Answer - 15827

5. Geometric Series

Example 1. 5, 35, 245, 1715, ?

Ans. 12005

Examples 2. 43923,3993, 363, 33, ?

Ans. 3

6. Two-tier Arithmetic Series

7. Other Type

To find the odd number from the number series. In this type of series the above rules are also followed.

Some Examples ;

2, 3, 7, 22, 89, 440, 2677, 18740

Solution : ×1+1, ×2+1, ×3+1, ×4+1, ×5+1 ........
So, 440 is replaced by 446

5, 6, 14, 40, 89, 170, 291

Solution : +12, +32, +52, +72, +92

So, 14 is replaced by 15.

445, 221, 109, 46, 25, 114, 4

Solution : -3÷2, -3÷2........

So,46 is replaced by 53.
12, 26, 56, 116, 244, 498, 1008

Solution : ×2+2, ×2+4 ×2+6, ........

So, 116 is replaced by 118

8, 27, 64, 125, 217, 343

Solution : 23, 33, 43, 53,.....

So, 217 is replaced by 216

Three Steps to Solve A Problem on Series

Step 1. Determine whether the series is increasing, decreasing or alternating.

Step 2. If the series is increasing or decreasing, then check :

if change is slow or gradual, then it is a difference series
if the change is equally sharp, throughout, then it is a ratio series.
if the rise is very sharp initially , but slows down later, then series may be formed by adding squared or cubed numbers

If the series is alternating or irregular , there may be either a mix of two series or two different kinds of operations going on alternately.

Step 3. Complete the series accordingly.

Number Series Math Shortcuts Tricks

Number Series puzzles can be solved by various tricks provided by mathematics.

Firstly check the direct formulas as in like check

if all the numbers are prime, even or odd.
If all the numbers are perfect squares or cubes.
If all the numbers have a particular divisibility.
If all the numbers are succeeding by some additions or subtraction or multiplications or divisions by a particular number or addition of their cubes and squares. Number series methods are teaches by a professional to a student so that number series can be solved quickly and correctly.

The given sequences of numbers will be such that every number takes after its predecessor in the same way, i.e., according to a particular pattern. Hopefuls are required to figure out the right ways in which the sequence is formed and thereafter find out the number to finish the arrangement.

30, 34, 43, 59, 84, 120,?

(1) 169

(2) 148

(3) 153

(4) 176

(5) None of these

Solution: (1) The given pattern is:

+22, 32, +42, + 62, +72

So, missing term is 169=120 +72

40, 54, 82, ?, 180 ,250

(1) 142

(2) 124

(3) 136

(4) 163

(5) None of these

Solution: (2) The pattern is: +14, + 28, + 42, + 52, + 70

So, missing term is 82 + 42=124

Type 2 – In this we are given a sequence of number. The whole sequence, except the odd number, follow a certain rule. You need to search that number which does not follow the rule.

0, 1,3,8,18,35,264

(1) 62
(2) 35
(3) 18
(4) 8
(5) None of these

Solution: (1) The pattern is +(02+1), +(12+1), + (22+1) ,+ (32+1), + (42+1), + (52+1)
So, 62 is wrong and must be replaced by 35 + (52+1) = 62

1, 9, 125, 49, 729, 121, 2147

(1) 2147
(2) 729
(3) 125
(4) 1
(5) None of these
Solution: (1)

Some of the questions asked in number series previous papers –

Directions: (1-5) In each of these questions a number series is given. In each series stand out number isn’t right. Discover the wrong number. (IBPS CWE PO/MT Exam 2012)

5531 5506 5425 5304 5135 4910 4621

(1) 5531
(2) 5425
(3) 4621
(4) 5135
(5) 5506
Solution: The number should be 5555 in place of 5531.

-72, -92, -112, -132, -152, -172…
Ans: (1)

6 7 9 13 26 37 69

(1) 7
(2) 26
(3) 69
(4) 37
(5) 9

Solution: The number should be 21 in place of 26.

+1, +2, +4, +8, +16, +32

Ans: (2)

1 3 10 36 152 760 4632

(1) 3
(2) 36
(3) 4632
(4) 760
(5) 152

Solution: The number should be 770 In place of 760.

×1 +2, ×2 +4, ×3 +6, ×4 + 8, ×5 +10, ×6 + 12, …
Ans: (4)

4 3 9 34 96 219 435

(1) 4
(2) 9
(3) 34
(4) 435
(5) 219

Solution: The series is 02+ 4, 12+2, 32+0, 62-2, 102-4, 152- 6,212 – 8…

Hence, 435 should be replaced with 433

Ans: (1)

157.5 45 15 6 3 2 1
(1) 1
(2) 2
(3) 6
(4) 157.5
(5) 45
Solution: The number should be 2 in place of 1.

3.5, 3, 2.5, 2, 1.5, 1, .

Tag : Number Series

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