Verbal Reasoning : : Number Series Questions & Answers

Verbal Reasoning
Number Series

2, 6, 12, 20, 30, 42, 56, ?

A. 70

B. 61

C. 64

D. 72

Answer : Option D

Explanation :

In this problem the given series follows the following pattern of n x (n + 1) where n = 1, 2, 3, 4, ... i.e.

1st term = 1 x (1 + 1) = 2

2nd term = 2 x (2 + 1) = 6

3rd term = 3 x (3 + 1) = 12

4th term = 4 x (4 + 1) = 20

5th term = 5 x (5 + 1) = 30

6th term = 6 x (6 + 1) = 42

7th term = 7 x (7 + 1) = 56

8th term = 8 x (8 + 1) = 72

So, the missing term is 72.

Find out the wrong number in the given series:
15, 18, 20, 29, 45, 70, 106

A. 18

B. 20

C. 29

D. 45

Answer : Option A

Explanation :

The pattern is +1, +4, +9, +16, ... i.e. +1², +2², +3², +4², ... . Therefore change 18 to 16 to statisfy the condition i.e.

1st term = 15 + 1 = 16

2nd term = 16 + 4 = 20

3rd term = 20 + 9 = 29

4th term = 29 + 16 = 45

5th term = 45 + 25 = 70

6th term = 70 + 36 = 106.

So, the wrong number in the given series is 18.

82, 107, 207, 432, 832, ?

A. 1550

B. 1450

C. 1457

D. 1542

Answer : Option C

Explanation :

The difference between the consecutive numbers follows the pattern of 25n² where n = 1, 2, 3, 4, ... .Let X be the missing term. There are two steps to solve the given series i.e.

Step 1	Step 2
107 - 82 = 25	25 x 1² = 25
207 - 107 = 100	25 x 2² = 100
432 - 207 = 225	25 x 3² = 225
832 - 432 = 400	25 x 4² = 400
X - 832 = 625	25 x 5² = 625

∴ Missing term = X = 625 + 832 = 1457

10, 50, 94, 142, 194, ?

A. 250

B. 260

C. 270

D. 280

Answer : Option A

Explanation :

The pattern is of double difference. Let X be the missing term. There are two steps to solve the given series i.e.

Step 1	Step 2
50 - 10 = 40	-----
94 - 50 = 44	44 - 40 = 4
142 - 94 = 48	48 - 44 = 4
194 - 142 = 52	52 - 48 = 4
X - 194 = 56	56 - 52 = 4

∴ Missing term = X = 194 + 56 = 250

3, 12, 27, 48, 75, 108, ?

A. 147

B. 183

C. 162

D. 192

Answer : Option A

Explanation :

In this problem the given series follows the following pattern of 3n² where n = 1, 2, 3, 4, ... i.e.

1st step = 3 x 1² = 3 x 1 = 3

2nd step = 3 x 2² = 3 x 4 = 12

3rd step = 3 x 3² = 3 x 9 = 27

4th step = 3 x 4² = 3 x 16 = 48

5th step = 3 x 5² = 3 x 25 = 75

6th step = 3 x 6² = 3 x 36 = 108

7th step = 3 x 7² = 3 x 49 = 147

So, the missing term is 147.