Simplifying Quantitative Aptitude: Concepts & Tricks for solving Questions in Number Series

Number Series is one of the important and scoring sections of Quantitative Aptitude for bank exams including SBI and IBPS Exams. Question from Number Series are asked in all bank exams.

How to Score More in SBI PO and IBPS PO Exams: Scoring more in Number Series questions is easier for those who are comfortable with numbers and their relations. One has to understand different type of relation among numbers. The relation among numbers can be divided into the following types-

Tips to solve Number Series Questions

Identifying the right sequence → Get Mathematical Sequence → Find the Number

The following example will help to identify the relation among numbers:

Ex1: 10, 16, 22, 28, ?

Solution: 10+6= 16; 16+6= 22; 22+6=28; 28+6=34

Answer: 34

Ex2: 10, 16, 14, 20, 18, 24, 22, ?

Solution: Here the sequence can be achieved by +6, -2, +6, -2, …..

10+6=16; 16-2=14; 14+6=20; 20-2=18; 18+6=24; 24-2=22; 22+6=28

Answer: 28

Ex3: 10, 14, 23, 39, 64, ?

Solution: Here the sequence can be achieved by adding +2², +3², +4², +5², …

10+2² (4)=14; 14+3²(9)= 23; 23+4²(16)=39; 39+5²(25)=64; 64+6²(36)=100

Answer: 100

Ex4: 10, 12, 14, 20, 32, 62, ?

Solution: Here the sequence can be achieved by adding: +1²+1; +2²-2 +3²+3; +4²-4; +5²+5; +6²-6…

Questions from IBPS CWE PO/MT 2012:

Directions: (1-5) In each of these questions a number series is given. In each series only one number is wrong. Find out the wrong number.

Q1) 5531   5506   5425   5304   5135   4910 4621

(1) 5531

(2) 5425

(3) 4621

(4) 5135

(5) 5506

Solution: Here the sequence can be achieved by -7², -9², -11², -13², -15², -17²…

Ans: (1)

Q2)  6   7   9   13   26   37   69

(1) 7

(2) 26

(3) 69

(4) 37

(5) 9

Solution: Here the sequence can be achieved by adding  +1, +2, +4, +8, +16, +32

Ans: (2)

Q3)  1   3   10   36   152   760   4632

(1) 3

(2) 36

(3) 4632

(4) 760

(5) 152

Solution: Here the sequence can be achieved by  ×1 +2, ×2 +4, ×3 +6, ×4 + 8, ×5 +10, ×6 + 12, …

Ans: (4)

Q4)  4   3   9   34   96   219   435

(1) 4

(2) 9

(3) 34

(4) 435

(5) 219

Solution: Here the sequence can be achieved by adding 0²+ 4, 1²+2, 3²+0, 6²-2, 10²-4, 15²– 6,21² – 8…

Hence, 435 should be replaced with 433

Ans: (1)

Q5)  157.5     45   15   6   3   2   1

(1) 1

(2) 2

(3) 6

(4) 157.5

(5) 45

Solution: Here the sequence can be achieved by  3.5, 3, 2.5, 2, 1.5, 1, …

Ans: (1)