Wrong Number Series is usually asked in all banking exams & it is an important topic as 3-5 questions are asked from this chapter. We will be given series which follows a certain pattern except one number & our job is to identify that number which does not follow that pattern & gave the answers accordingly.

Directions (1-7): In the following number series, a wrong number is given. Find out that wrong number.

Ques 1: 1  4  25  256  3125  46656  823543

Ques 2. : 2  6  15  30  45  43.5  22.5

Ques 3: 4          5          13           40           108           229             445

Ques 4: 18000  3600  720    148.5        28.8  5.76

Ques 5. : 1.7                3.2            2.7            4.3 3.7       5.2           4.7

Ques 6. : 3  4  13  38   87     165289

Ques 7: 8,  11,  17,  31,  65,  165.5, 498.5

1. The pattern of the number series is:

11 = 1          2² = 4              33 = 27  44 = 256          55 = 3125 66 = 46656

So, the wrong number in the series is 25.

2.The pattern of the number series is:

2 × 3 = 6                                       6 × 2.5 = 15                                   15 × 2 = 30

30 × 1.5 = 45                           45 × 1 = 45 [43.5]                           45 × 0.5 = 22.5

So, the wrong number in the series is 43.5

3.The pattern of the number series is:

4 + 1³ = 5                                      5 + 2³ = 13                                     13 + 3³ = 40

40 + 4³ = 104                    104 + 5³ = 229                                229 + 6³ = 445

So, the wrong number in the series is 108

4. The pattern of the number series is:

18000 / 5 = 3600                       3600 / 5 = 720                              720 / 5 = 144 [148.5]

144 / 5 = 28.8                            28.8 / 5 = 5.76

So, the wrong number in the series is 148.5

5.The pattern of the number series is:

1.7 + 1.5 = 3.2                           3.2 – 0.5 = 2.7                                    2.7 + 1.5 = 4.2 [4.3]

4.2 – 0.5 = 3.7                           3.7 + 1.5 = 5.2                                    5.2 – 0.5 = 4.7

So, the wrong number in the series is 4.3

6.The pattern of the number series is:

4 – 3 = 1²                                    13 – 4 = 9 = 3²                                    38 – 13 = 25 = 5²

87 – 38 = 49 = 7²                   168 – 87 = 81 = 9²                          289 – 168 = 121 = 11²

So, the wrong number in the series is 165

7.The pattern of the number series is:

8 × 0.5 + 7 = 4 + 7=11

11 × 1 + 6 = 17

17 × 1.5 + 5 = 25.5 + 5 = 30.5 

30.5 × 2 + 4 = 61 + 4 = 65

So, the wrong number in the series is 31