# Number Series Questions for IBPS PO Prelims 2020

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Number Series Questions for IBPS PO Prelims 2020: Number series is an important topic and requires a lot of practice because the series can follow any logic hence it is very important that you do the rigorous practice of this topic to ace this.

This topic comes in both prelims and mains examination and carries a lot of weightage in the examination. In prelims, this topic carries 5 questions for 5 marks and in mains also you can get these questions for 4 marks. Considering the importance of this topic we will be covering it in this article. Make sure you read it well and understand the concept.

Earlier, number series were asked in the form of the missing number.But, seeing some recent exams, it has been found that the latest pattern of number series is to identify wrong numbers given in the series. In this article, we will discuss this latest pattern.This latest pattern is nothing but an advanced pattern of missing numbers.

If you know the basics of number series, then it will be easier for you. Number Series Rules with solved Problems Series is an important chapter from the banking examination point of view. Following are some of the important rules or order on which the number series can be made:-

• Pure Series
• Difference Series
• Ratio Series
• Mixed Series
• Geometric Series
• Two Tier Arithmetic Series
• Other Types

### 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 SquareExample :121, 144, 169, 225 ?Answer – 256Perfect CubeExample :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

### 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, 18740Solution : ×1+1, ×2+1, ×3+1, ×4+1, ×5+1 …….. So, 440 is replaced by 4465, 6, 14, 40, 89, 170, 291Solution : +12, +32, +52, +72, +92 So, 14 is replaced by 15.445, 221, 109, 46, 25, 114, 4Solution : -3÷2, -3÷2……..So,46 is replaced by 53.12, 26, 56, 116, 244, 498, 1008Solution : ×2+2, ×2+4 ×2+6,  ……..So, 116 is replaced by 1188, 27, 64, 125, 217, 343Solution : 23, 33, 43, 53,…..So, 217 is replaced by 216

### Things You Must Know Before Starting This Topic

Given below is the list of things that you must remember by heart to ace this topic:

• Learn tables up to 25
• Learn Squares up to 25
• Learn Cubes up to 25
• Learn Fractions up to 25

### Previous Year Asked Number Series in IBPS PO

Directions (1-15): Find the value of missing number (?) in the given number series.
Q1. 17,     18,     26,     35,     99,     ?
(a) 224
(b) 124
(c) 148
(d) 164
(e) 225

Q2. 23,     40,     74,     142,     278,     ?
(a) 392
(b) 478
(c) 544
(d) 496
(e) 550

Q3. 69,     82,     71,     80,     73,     ?
(a) 78
(b) 77
(c) 79
(d) 83
(e) 86

Q4. 53,     58,     75,     112,     177,     ?
(a) 261
(b) 275
(c) 278
(d) 285
(e) 317

Q5. 23,     40,     64,     96,     137,     ?
(a) 197
(b) 188
(c) 183
(d) 192
(e) 201

Q6. 23 ,     25,     79,     401,     2815,     ?
(a) 25345
(b) 25340
(c) 25350
(d) 25445
(e) 25355

Q7. 14/3,     8,     14,     24,     40,     ?
(a) 45
(b) 85
(c) 70
(d) 65