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Number Series - Solved Questions Verbal Reasoning – Number Series Problem 1 1 .        5, 7, 10 , 14,__ a) 17              b)19     ...

02. 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 , 22,23, 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 2nd 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 :
2ND  term is the power  4 of the 1st term , 14 =1    and 4th term is power 4 of the 3rd 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 :
2nd term => 6 x 4 =24
4th term => 5 x 5 =25
6th 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 2nd series. The logic in 2nd 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 2nd 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 2nd 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 33.. 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 2nd  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