Verbal Reasoning for Campus Placement Papers --- NUMBER SERIES Solved Questions

Number Series - Solved Questions

Verbal Reasoning – Number Series Problem 1
1.       5, 7, 10 , 14,__

a) 17             b)19                      c)20                       d)22             e)25

Answer: B

Explanation :

The difference between two consecutive numbers is increasing in the order of 2,3,4,5, etc.

Verbal Reasoning – Number Series Problem 2
2.       0, 7, 26, 63, 124, _

a) 216           b)215                     c)217                               d)324                    e)219

Answer: B

Explanation :

The logic here is (1³ -1), (2³ -1), (3³ -1), (4³ -1), (5³ -1) and (6³ -1), 

The answer is 215

Verbal Reasoning – Number Series Problem 3
3.       6, 8 ,14, 22, 36,_

a)50               b)72                      c)58                     d)62             e)63

Answer: C

Explanation :

The logic here is  6+8=14 , 8+14=22, 14+22=36 .

So the answer is 22+36 =58

Verbal Reasoning – Number Series Problem 4
4.       7, 13, 17, 19, 23,_

a)25              b)27                      c)29                        d)30           e)31

Answer: C

Explanation :

The given numbers are series of consecutive prime numbers. 

The series can be completed by the next prime number 29.

Verbal Reasoning – Number Series Problem 5
5.       10, 22, 38, 58, 82,_

a)100                     b)110            c)120                               d)130            e)134

Answer: B

Explanation :

10,   22,   38,   58,   82            

  +12   +16  +20  +24    

The difference between two consecutive numbers is increasing by 4.

The series can be completed by adding     24+4 =28 to 82.

The answer is 110.

Verbal Reasoning – Number Series Problem 6
6.       5, 8, 9, 12, 13, 16, 17, __

a)18                       b)19               c)19.5                    d)21           e)20

Answer: E

Explanation :

There are two series 5,9,13,17  and 8,12,8,16,__  with equal difference of 4 everywhere

So the answer is 16+4=20

Verbal Reasoning – Number Series Problem 7
7.       11 , 33 , 55 , 77 , 99 , _

a )101                     b)111           c)121                     d)131                     e)135

Answer: C

Explanation :

All numbers in the series are consecutive odd multiples of 11. 1*11, 3*11, 5*11, 7*11,9*11 .

The next number will be 11*11 =121

Verbal Reasoning – Number Series Problem 8
8.       54 ,36 , 81 ,63 , 27 , _

a)19                        b)25              c)46                     d)45             e)48

Answer:  D

Explanation :

The sum of the digits of each number is equal to 9, 

 i.e, 5+4=9 ,3+6 =9, 8+1 =9,6+3 =9 and 2+7 =9.

In the given choices 4+5=9 .So the answer is 45

Verbal Reasoning – Number Series Problem 9

9.       25, 35, 45, 37, 56, _

a)73                       b)84              c)87                      d)95             e)88

Answer: B

Explanation :

Add unit and tens digit of every member and they have consecutive increasing numbers , i.e., 2+5=7, 3+5=8, 4+5=9, 3+7=10, 5+6=11. 

So the next number will be   84 ,   8+4=12

Verbal Reasoning – Number Series Problem 10
10.   3, 15 ,35, 63, 99 ,143,_        

a)168                     b)170                c)196                  d)192           e)195

Answer: E

Explanation :

The given numbers in the series are based on logic of 2² -1 , 4² -1,6² -1,8² -1, 10² -1 and 12² -1.Thus even consecutive numbers are squared then 1 is subtracted . 

The next number will be  14² -1 =195

Verbal Reasoning – Number Series Problem 11
11.   1, 1, 4, 8 , 9 , 27 , 16 , 64 , __

a)20               b)25                    c)30              d)125           E)None Of these

Answer:B

Explanation :

The numbers in the gives series is 1²,1³ , 2²,2^3, 3²,3³, 4². 

So the missing number can be 4²

Verbal Reasoning – Number Series Problem 12
12.   1 ,19 55 ,109 ,181,__

a)271             b)250                     c)290             d)281                   e)290

Answer: A

Explanation :

The differences are 18,36,54,72  which are  consecutive multiples of 18.  The next number will be obtained by adding the next multiple of 18 , that is 90 to 181  . 

So the answer is 271

Verbal Reasoning – Number Series Problem 13
13.   4, 22, 76, 112,__

a)184             b)112                    c)150                     d)140            e)192

Answer: A

Explanation :

The difference between two consecutive numbers is divisible by 18.

Verbal Reasoning – Number Series Problem 14
14.   6, 11 , 8 , 7 , 10 , 3 , 12 , _

a)4                          b)2                      c)0                 d)-1            e)None of these

Answer: D

Explanation :

There are two series  6,8,10,12   and 11,7,3,_   The missing number is in 2^nd series .So next number is formed by subtracting 4 from previous number  . 

The answer is 3-4=-1

Verbal Reasoning – Number Series Problem 15
15.   5, 7, 11 ,17 , 25 , 35 , __

a)43                       b)44              c)46             d)47            e)50

Answer: D

Explanation :

The difference between two consecutive number are increasing in the order of 2,4,6,8,10.So the next will be 35+12=47.

Verbal Reasoning – Number Series Problem 16
16.   4 , 6 , 12 , 14 , 28 , 30 , 60 , _

a)65               b)120                   c)64                d)66          e)62

Answer: E

Explanation :

4+2 =6 , 6 *2 =12 , 12+2=14 , 14*2 =28 . 28+2=30, 30*2=60 , 60+2=62 .The next number is 60+2=62

Verbal Reasoning – Number Series Problem 17
17.   10 ,5 , 20 ,10 , 40 , 20 , 80 , _

a)30                b)40                     c)50              d)60           e)45

Answer:

Explanation :

There are two series 10,20,40,80,  and 5,10,20,__ and every next number is double of the preceding one. 

So the answer is 20 *2 =40

Verbal Reasoning – Number Series Problem 18
18.   4, 6 , 10 , 18 , 34 , _

a)45               b)66             c)72                      d)80            e)64

Answer:

Explanation :

The difference between two consecutive numbers are 2,4,8,16 . Each time the difference is doubled. 

So next number will be increased by 16* 2=32

Verbal Reasoning – Number Series Problem 19
19.   65 ,32 , 87 , 21 , _

a)63             b)85               c)16                      d)98           e)       None of these

Answer: D

Explanation :

Subtracting unit digit from tens digit, we will get 1 everywhere.

6-5 =1  ,3-2 =1, 8-7=1 ,2-1=1  .From the given options  , 9-8=1   

So 98 is the answer.

Verbal Reasoning – Number Series Problem 20
20.   24, 19 , 12 ,7 , 2 , _

a)0                   b)1                      c)-1                      d)-3             e) None of these

Answer: D

Explanation :

Next number is obtained by subtracting 5 from the previous number.

24 -5 = 19,   19-5 =12 ,12-5= 7, 7-5 =2 .

So next number will be 2-5 =-3.

Verbal Reasoning – Number Series Problem 21
21.   7, 16 , 34 ,70 ,142 , _

a)282                b)284                 c)286                     d)290            e) 294

Answer: C

Explanation :

The logic is 7 x 2 +2 =16   , 16 x 2+2 =34 , 34 x 2 +2 =70 , 70 x2 +2=142. So the next number will be 142 x 2+2= 286

Verbal Reasoning – Number Series Problem 22
22.   40, 60, 80, 30 ,160 ,15 ,320 , _

a)680                        b)7.5                    c)5              d)480            e)10.5

Answer: B

Explanation :

It is the combination of two series  .

The first series is 40,80,160,320 . Each number is formed by doubling the previous number

The second series is  60,30,15,__  .In this series , the numbers are being halved i.e = 30, =  15. 

So the missing number will be =7.5

Verbal Reasoning – Number Series Problem 23
23.   1, 1,  2,  16  ,3  ,81  ,4  , _

a)64               b)128                    c)256             d)512                   e)625

Answer: C

Explanation :

2^ND  term is the power  4 of the 1^st term , 1⁴ =1    and 4^th term is power 4 of the 3^rd term 2⁴ =16 and so on . 

The answer is 4⁴=256

Verbal Reasoning – Number Series Problem 24
24.   3, 10, 29 ,66 ,127 ,218 , _

a)341              b)343                    c)344                     d)345           e)None of these

Answer:D

Explanation :

Every next number is a cube of the preceding number +2  I .e,

1³ +2 =3   , 2³ +2 =10 , 3³ +2 =29 , 4³ +2 =66 , 5³ +2 =127 , 6³ +2 =, 218  So the missing number will be 7³ +2 =345.

Verbal Reasoning – Number Series Problem 25
25.   7, 35 ,140 ,420 ,840 , __

  a)  1680               b)1360                      c)840              d)0           e)1

Answer: C

Explanation :

 7 x 5 =35 , 35 x 4=140 , 140 x 3=420 , 420 x 2= 840. The multipliers are in the decreasing order 5,4,3,2. 

So the next number is 840 x 1 =840.

Verbal Reasoning – Number Series Problem 26

26.   6, 24 ,5 ,25 ,24 ,144 ,18 ,  _

a)126                     b)116                       c)106                   d)96             e)184

Answer: A

Explanation :

2^nd term => 6 x 4 =24

4^th term => 5 x 5 =25

6^th term => 24 x 6 =144

Multipliers are in the increasing order 4,5 and 6.

So the missing number will be 18 x 7 =126

Logical  Reasoning – Number Series Problem 27
27.   25 ,100 ,255 , 400 , _

a)550              b)625                   c)675             d)800           e)None of these

Answer: B

Explanation :

Dividing all the term of the series by  25 , we get the quotients  1,4,9,16 ( Perfect squares)

So to get next number will be obtained by multiplying the next square number by 25.

25 x 25 =625 .

Logical Reasoning – Number Series Problem 28
28.   10 ,22 ,40 ,64 ,94 ,130 , __

a)166              b)172                   c)180            d)206            e)216

Answer: B

Explanation :

The difference between the consecutive terms is 12, 18, 24, 30, 36. The difference is increased by 6. So the missing number will be obtained by adding 36+6= 42 .   So the answer is 130+42=172

Verbal Reasoning – Number Series Problem 29
29.   14 , 34 , 74 , 154 , 314 , _

a)604               b)624                  c)614                     d)524            e)634

Answer: E

Explanation :

34- 14 =20 , 74-34 =40 , 154 -74 =80 and 314-154 =160 .So the difference is doubled each time. The next number will be obtained by adding 160 *2 =320  . So the answer is 314+ 320 =634

Logical Reasoning – Number Series Problem 30
30.   64 , 5, 32 , 15 , 16 , 45 , 8 , 135 , __

a)6                  b)4                      c)2              d)0               e)10

Answer: B

Explanation :

There are two series 5,15,45,135   and 32,16,8,_

The missing term is in 2^nd series. The logic in 2^nd series is  =32, =16 ,  =8 .So the missing number is  =4.

Verbal Reasoning – Number Series Problem 31
31.   600 , 300 , 150 , 75 , _

a)36                b)37.5                           c)38             d)40             e)None of thes

Answer: B

Explanation :

Each next number is is half of the preceding number .

Logical Reasoning – Number Series Problem 32

32.   88, 75 ,85 ,78 ,82 ,81 ,79 ,  _

a)81                b)78             c)82                     d)84            e)97

Answer: D

Explanation :

There are two series  . The first series  is 88,85,82,79 . Each next number is obtained by subtracting  3 to preceding number

The second series is 75,78,81,__. Each next number is obtained by adding 3 to preceding one.So the answer is 81 +3 =84

Verbal Reasoning – Number Series Problem 33
33.   53, 35 , 64 , 46 , 18 , 81 , 49 ,  _

a)98                        b)94                      c)96             d)58             e)104

Answer: B

Explanation :

Every second number is the reverse of the preceding number. So the reverse number of 49 is 94.

Verbal Reasoning – Number Series Problem 34

34.   5 , 3 , 15 , 7 , 4 , 28 , 8 , 7 , _

a)15                   b)42                  c)56              d)63           e)70

Answer: C

Explanation :

5 x 3 =15 , 7 x 4= 28  . So the next number will be 8 x 7 =56

Logical Reasoning – Number Series Problem 35

35.   11 , 52 , 22 , 39 , 33 , 26 , 44 , 13 , 55 , _

a)10              b)66              c)68                     d)5               e)0

Answer: E

Explanation :

There are two series   11,22,33,44,55 and  52,39,26,13,_.

The missing number is in 2^nd series .  In this series  , each next number is obtained by subtracting 13 from the previous number. 

So the answer is 13- 13 =0

Logical  Reasoning – Number Series Problem 36
36.   121 , 11 , 81 , 9 , 49 ,7 , 25 , _

a)10                       b)7               c)5                d)3              e)None of these

Answer:C

Explanation :

First number is the square of 2^nd number in every pair such 121=11²  , 81 = 9² , 49 = 7²  and 25 = 5² .

Answer is 5

Logical Reasoning – Number Series Problem 37
37.   4 , 8 , 9 , 18 , 12 , 24 , 17 , _

a)34              b)30             c)32                      d)29             e)35

Answer: A

Explanation :

Second number is double of the first number in every pair = 4 x 2= 8,  9 x 2 =18 , 12 x 2 =24. Answer is 17 x 2 =34

Logical Reasoning – Number Series Problem 38

38.   5, 4 , 9 , 13 , 17 , _ , 47

a)25                b)30              b)35           d)40             e)41

Answer:  B

Explanation :

Each number sum of the its two preceding numbers.

5+ 4=9 ,4+9=13,13+17=30 and 17+30=47.

So the answer is 30

Logical Reasoning – Number Series Problem 39

39.   1, 2 , 3 , 1 , 4 , 9 , 1 , 8 , _

a)16             b)21              c)27             d)32            e)35

Answer: C

Explanation :

Here the logic is 1,2,3,1²,2²,3² ,1³,2³ and 3^3.. Answer is 3³ =27

Logical Reasoning – Number Series Problem 40

40.   6, 15 , 14 , 19 , 30 ,27 , _ , _

a)62 ,43                   b)60,41              c)31,45              d)64,45        e)None of these

Answer: A

Explanation :

Here we find two alternate series

i.e, 6,14,30,_  and 15,19,27,_

In the first series differences between two consecutive numbers of the series are 8,16. Here the difference is doubled each time. So the missing number will be obtained by adding 32  to 30. 30+30=62

In the 2^nd  series ,differences between two consecutive numbers of the series are 4,8. Here the difference is doubled each time. So the missing number will be obtained by adding 16 to 27. 27+16=43

Logical Reasoning – Number Series Problem 41

41.   5 , 16 , 51 , 158 ,  _

a)325              b)481                    c)483                    d)495            e)564

Answer:B

Explanation :

 5 x 3+1 =16  , 16 x 3 +3 =51 , 51 x 3 +5=158. 

Therefore the next numbers is 158 x 3 + 7 =481

Logical Reasoning – Number Series Problem 42

42.   17542 , 24571 ,57152 , 41571 , 47541 , _

a)57161                  b)54291                   c)72451           d)17543     e)None of these

Answer: C

Explanation :

Each of the given numbers contains similar digits but places of these digits are different in each subsequent number.

The common digits in all numbers are 1,2,4,5,7

In option C , the number 72451 has similar digits

Logical Reasoning – Number Series Problem 43

43.   5731, 6802 , 7243 , 9700 , _

a)9341                      b)1951                  c)35468             d)10655              e)9582

Answer: B

Explanation :

In each of the given numbers, sum of the digits is equal to 16.

From the  given options, 1951 =1+9+5+1 =16 .

Therefore answer is 1951

Logical Reasoning – Number Series Problem 44

44.   52,34,61,70,_

a)43                       b)45                        c)53                      d)81             e)72

Answer: A

Explanation :

Sum of the units and tens digit of each number is equal to 7.

For the given options,  4+3 =7.

Logical Reasoning – Number Series Problem 45

45.   3, 7, 13, 21 ,31 , 43 , _

a)49                       b)57               c)65                      d)61            e)68

Answer: B

Explanation :

Each next number of the given series is increasing in the order of 4,6,8,10,12. The missing number will be obtained by adding 14 to 43  . 43 + 14 =57

Logical Reasoning – Number Series Problem 46

46.   8, 10 , 13 , 17 , 22 , _

a)24              b)26             c)27                      d)28                   e)30

Answer: D

Explanation :

8,    10,    13,   17,    22,   28

  +2   , +3  ,  + 4  , + 5   +6

Difference between each number is increased by 1.

Logical Reasoning – Number Series Problem 47

47.   144 , 72 ,36 , 18 , _

a)10                       b)9                  c)8                       d)7              e)6

Answer:D

Explanation :

Each number is half of its previous number. So the answer is  = 9

Logical Reasoning – Number Series Problem 48

48.   2, 6, 12 , 20 , 30 , 42 , 56 , _

a)62               b)64                     c)68              d)70                      e)72

Answer:E

Explanation :

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

1x2=2, 2x3=6 , 3x4 =12, 4x5=20, 5x6=30 ,6 x7=42, 7x8=56

The logic here is each number is product of two consecutive natural numbers.

 So the answer is 8 x 9=72

Logical Reasoning – Number Series Problem 49

49.   69 , 77 , 71 , 79 , 73 , _

a)81              b)85            c)65             d)67             e)None of these

Answer: A

Explanation :

69,     77,    71,    79,   73. The answer is 73 +8 =81

 +8        -6      +8     -6.

Logical Reasoning – Number Series Problem 50

50.   37 , 41 ,43 , 47 , _ , 5 9

a)51                 b)53                      c)55             d)57            e) 58

Answer: B

Explanation :

All the given numbers are consecutive prime numbers. The answer is 53