# Reasoning – Number Series MCQ-1

Q 1. 1, 9, 25, 49, ?, 121. What will come at the place of question mark ?

A) 100
B) 91
C) 64
D) 81

Solution:
12 = 1.
32 = 9.
52 = 25.
72 = 49.
92 = 81.
112 = 121.

Q 2. 4, 7, 12, 19, 28, ?

A) 49
B) 36
C) 30
D) 39

Solution:
First term,
4
Second,
4+3 = 7.
Third,
7+5 = 12.
Fourth,
12+7 = 19.
Fifth,
19+9 = 28.
Therefore,
28+11 = 39 will be the required term.

Q 3. 6, 11, 21, 36, 56, ?

A) 91
B) 51
C) 81
D) 42

Answer: Option CQ 4. 10, 100, 200, 310, ?

A) 430
B) 420
C) 410
D) 400
Solution:
1st term : 10
2nd term : 100 = 10+90
3rd term : 200 = 100+100
4th term : 310 = 200+110
5th Term: 430 = 310+120

Q 5. 8, 28, 116, 584, ?

A) 1752
B) 3504
C) 3508
D) 3502

Solution:
(8 *3) + 4 = 28
(28 *4) + 4 = 116
(116 *5) + 4 = 584
(584 *6) + 4 = 3508.

Q 6. 3, 7, 23, 95, ?

A) 62
B) 128
C) 479
D) 575

Solution:
1st number = 3
2nd number = 3 x 2 +1 = 7
3rd number = 7 x 3 + 2 = 23
4th number = 23 x 4 + 3 = 95
5th number = 95 x 5 + 4 = 479

Q 7. 7, 26, 63, 124, 215, 342, ?

A) 391
B) 511
C) 481
D) 421

Solution:
The terms are given in a series
(23 -1) = 7
(33 -1) = 26
(43 -1) = 63
(53 -1) = 124
(63 -1) = 215
(73 -1) = 342
So, the missing term is,
(83 -1) = 511.

Q 8. 165, 195, 255, 285, 345, ?
A) 390
B) 420
C) 435
D) 375
E) Two answer out of four option

Solution:
Solution 1:
Each number of given series is 15 multiplied by a prime number.
15*11, 15*13, 15*17, 15*19, 15*23.
So, Missing number is
15*29 = 435.
Solution 2:
This pattern is +30 and then +60 also follow for the give series.
165+30=195,
195+60=255,
255+30=285,
285+60=345,
345+30=375

Q 9. 34, 45, 56, 67…….

A) 78
B) 73
C) 82
D) 84

Answer: Option AQ 10. 3, 2, 7, 6, 11, ?

A) 8
B) 10
C) 4
D) 2
Solution:
2nd number is less by 1 than the 1st number and 3rd number is more by 5 than the 2nd number. The same rule follows in other numbers of the series.

Q 11. In the following number series a wrong number is given. Find out the wrong number.
150, 450, 750, 1060,1350,1650,1950

A) 1060
B) 1950
C) 450
D) 1350
E) 750

Solution:
By adding 300 to each term, we get the next term. 1060 is wrong term. It should be 1050.

Q 12. 5690, 5121, 4552, 3983, 3414, 2845, ?

A) 2276
B) 2516
C) 2356
D) 2456

Solution:
By subtracting 569, we get the next term.
Required number,
= 2845-569
= 2276.

Q 13. 6, 13, 28, 59, ?, 249.

A) 124
B) 122
C) 120
D) 118

Answer: Option BQ 14. 4, 8, 10, 14, 16, 20, ?

A) 22
B) 21
C) 20
D) 16
Solution:
Above series contains two sub-series in it.
4, 10, 16, 22
8, 14, 20
Each of both term there is difference of 6 i.e. next term is 6 greater than previous term.

Q 15. 9, 17, 33, 65, ?
A) 117
B) 119
C) 129
D) 99

Answer: Option CQ 16. 2, 3, 6, 15, ?, 123

A) 47
B) 42
C) 45
D) 50
[show_answer]Answer: Option BQ 17. In the following number series a wrong number is given. Find out the wrong number.
1, 3, 10, 21, 64, 129, 356, 777

A) 129
B) 21
C) 10
D) 356

A) 316
B) 1135
C) 1288
D) 2254

Q 19. 2, 7, 27, 107, 427, ?

A) 1262
B) 1707
C) 4027
D) 4207

Q 20. Sunday, Monday, Wednesday, Saturday, Wednesday, Monday, …..
A) Sunday, Sunday
B) Sunday, Monday
C) Sunday, Wednesday
D) Sunday, Saturday
Monday to Wednesday = One day gap.
Wednesday to Saturday = Two days gap.
Saturday to Wednesday = Three days gap.
Wednesday to Monday = Four days gap.
In the next term there must be five days and six days gap.
So, Next term would be Sunday, Sunday.

Q 21. 2816, ? , 176, 44, 11.

A) 704
B) 1408
C) 352
D) 2640

Solution:
Logic: Next term = Previous term /4
2816 /4 = 704
704 /4 = 176.
176 /4 = 44.
44 /4 = 11.

Q 22. 113, 225, 449, ? , 1793

A) 897
B) 789
C) 987
D) 978

Solution:
113
113 * 2 = 226 -1 = 225
225 * 2 = 450 -1 = 449
449 * 2 = 898 – 1 = 897
897 * 2 = 1794 -1 = 1793

Q 23. Which of the following will come in place of the question mark (?) in the following sequence?

PRODUCTIVITY, RODUCTIVIT, ODUCTIVI, ?

A) DUCTIV
B) DUCTLY
C) UCTIV
D) DUCTI

Solution:
PRODUCTIVITY = RODUCTIVIT.(Bold letters are removed.)
RODUCTIVIT = ODUCTIVI.
ODUCTIVI = DUCTIV.

Q 24. 6, 24, 60,120, 210, ?

A) 336
B) 366
C) 330
D) 660

Solution:
First Number = 1 *2 *3 = 6
Second Number = 2*3*4 = 24
Third Number = 3*4*5 = 60
Fourth Number = 4*5*6 = 120
Fifth Number = 5*6*7 = 210
Sixth Number = 6*7*8 = 336.
Alternatively,
2*2*2-2=6
3*3*3-3=24
4*4*4-4=60
5*5*5-5=120
6*6*6-6=210
7*7*7-7=336.

Q 25. 6, 11, 31, 121, 601, ?

A) 3600
B) 3621
C) 3601
D) 3611

Solution:
Logic:
First Term = 6.
Second term = 6*2 -1 = 11.
Third term = 11* 3 – 2 = 31.
Fourth term = 31 *4 – 3 = 124 -3 = 121.
Fifth term = 121*5 – 4 = 601.
Sixth term = 601 *6 = 3606 – 5 = 3601.

Q 26. 7, 11, 19, 35, 67, ?
A) 99
B) 131
C) 137
D) 124

Solution:
Logic:
Last Term *2 – 3 = Next Term.
First Term = 7.
Second Term = 7 *2 -3 = 11.
Third Term = 11 *2 – 3 = 19.
Fourth Term = 19 *2 – 3 = 35.
Fifth Term = 35 *2 – 3 = 67.
Sixth Term = 67 *2 -3 = 131.

Q 27. 8, 22, 64, 190, 568, ?
A) 1702
B) 7767
C) 6992
D) 6913

Solution:
Logic:
Previous Term *3 – 2 = Next term.
First Term = 8.
Second term = 8 *3 – 2 = 24 -2 = 22.
Third term = 22 *3 -2 = 64.
Fourth term = 64 *3 -2 = 190.
Fifth Term = 190 *3 – 2 = 568.
Sixth Term = 568 *3 -2 = 1704 -2 = 1702.

Q 28. 5760,2880,960, 240, 48, ?

A) 6
B) 8
C) 12
D) 16

Solution:
First Term = 5760.
Second term = 5760 /2 = 2880.
Third Term = 2880/3 = 960.
Fourth term = 960/4 = 240.
Fifth term = 240/5 = 48.
So,
Required term = 48/6 = 8.

Q 29. 2, 1, (1/2), (1/4), … What number should come next?
A) (1/3)
B) (1/8)
C) (2/8)
D) (1/16)

Solution:
This is a simple division series; each number is one-half of the previous number.
In other terms to say, the number is divided by 2 successively to get the next result.
4/2 = 2
2/2 = 1
1/2 = 1/2
(1/2)/2 = 1/4
(1/4)/2 = 1/8 and so on.

Q 30. 7, 10, 8, 11, 9, 12, … What number should come next?
A) 7
B) 10
C) 12
D) 13

Solution:
This is a simple alternating addition and subtraction series. In the first pattern, 3 is added; in the second, 2 is subtracted.

Q 31. 36, 34, 30, 28, 24, … What number should come next?
A) 20
B) 22
C) 23
D) 26

Solution:
This is an alternating number subtraction series. First, 2 is subtracted, then 4, then 2, and so on.

Q 32. 22, 21, 23, 22, 24, 23, … What number should come next?
A) 22
B) 24
C) 25
D) 26

Solution:
In this simple alternating subtraction and addition series; 1 is subtracted, then 2 is added, and so on.

Q 33. 53, 53, 40, 40, 27, 27, … What number should come next?
A) 12
B) 14
C) 27
D) 53

Solution:
In this series, each number is repeated, then 13 is subtracted to arrive at the next number.

Q 34. 21, 9, 21, 11, 21, 13, 21, … What number should come next?
A) 14
B) 15
C) 21
D) 23

Solution:
In this alternating repetition series, the random number 21 is interpolated every other number into an otherwise simple addition series that increases by 2, beginning with the number 9.

Q 35. 58, 52, 46, 40, 34, … What number should come next?
A) 26
B) 28
C) 30
D) 32

Solution:
This is a simple subtraction series. Each number is 6 less than the previous number.

Q 36. 3, 4, 7, 8, 11, 12, … What number should come next?
A) 7
B) 10
C) 14
D) 15

Solution:
This alternating addition series begins with 3; then 1 is added to give 4; then 3 is added to give 7; then 1 is added, and so on.

Q 37. 8, 22, 8, 28, 8, … What number should come next?
A) 9
B) 29
C) 32
D) 34

Solution:
This is a simple addition series with a random number, 8, interpolated as every other number. In the series, 6 is added to each number except 8, to arrive at the next number.

Q 38. 31, 29, 24, 22, 17, … What number should come next?
A) 15
B) 14
C) 13
D) 12

Solution:
This is a simple alternating subtraction series, which subtracts 2, then 5.

Q 39. 1.5, 2.3, 3.1, 3.9, … What number should come next?
A) 4.2
B) 4.4
C) 4.7
D) 5.1

Solution:
In this simple addition series, each number increases by 0.8.

Q 40. 14, 28, 20, 40, 32, 64, … What number should come next?
A) 52
B) 56
C) 96
D) 128

Solution:
This is an alternating multiplication and subtracting series: First, multiply by 2 and then subtract 8.

Q 41. 2, 4, 6, 8, 10, … What number should come next?
A) 11
B) 12
C) 13
D) 14

Solution:
This is a simple addition series. Each number increases by 2.

Q 42. 201, 202, 204, 207, … What number should come next?
A) 205
B) 208
C) 210
D) 211

Solution:
In this addition series, 1 is added to the first number; 2 is added to the second number; 3 is added to the third number; 4 is added to the fourth number; and go on.

Q 43. 544, 509, 474, 439, … What number should come next?
A) 404
B) 414
C) 420
D) 445

Solution:
This is a simple subtraction series. Each number is 35 less than the previous number.

Q 44. 80, 10, 70, 15, 60, … What number should come next?
A) 20
B) 25
C) 30
D) 50

Solution:
This is an alternating addition and subtraction series. In the first pattern, 10 is subtracted from each number to arrive at the next. In the second, 5 is added to each number to arrive at the next.

Q 45. 2, 6, 18, 54, … What number should come next?
A) 108
B) 148
C) 162
D) 216

Solution:
This is a simple multiplication series. Each number is 3 times more than the previous number.

Q 46. 5.2, 4.8, 4.4, 4, … What number should come next?
A) 3
B) 3.3
C) 3.5
D) 3.6

Solution:
In this simple subtraction series, each number decreases by 0.4.

Q 47. 8, 6, 9, 23, 87 , … What number should come next?
A) 128
B) 226
C) 324
D) 429

Solution:
8 x 1 – 2 = 6
6 x 2 – 3 = 9
9 x 3 – 4 = 23
23 x 4 – 5 = 87
87 x 5 – 6 = 429 …

Q 48. 28, 25, 5, 21, 18, 5, 14, … choose which pair of numbers comes next?
A) 11, 5
B) 10, 7
C) 11, 8
D) 5, 10
E) 10, 5

Solution:
This is an alternating subtraction series with the interpolation of a random number, 5, as every third number. In the subtraction series, 3 is subtracted, then 4, then 3, and so on.

Q 49. 8, 11, 21, 15, 18, 21, 22, … choose which pair of numbers comes next?
A) 25, 18
B) 25, 21
C) 25, 29
D) 24, 21
E) 22, 26

Solution:
This is an alternating addition series, with a random number, 21, interpolated as every third number. The addition series alternates between adding 3 and adding 4. The number 21 appears after each number arrived at by adding 3.

Q 50. 9, 16, 23, 30, 37, 44, 51, … choose which pair of numbers comes next?
A) 59, 66
B) 56, 62
C) 58, 66
D) 58, 65
E) 54, 61

Solution:
Here is a simple addition series, which begins with 9 and adds 7.

Q 51. 2, 8, 14, 20, 26, 32, 38, … choose which pair of numbers comes next?
A) 2, 46
B) 44, 50
C) 42, 48
D) 40, 42
E) 32, 26

Solution:
This is a simple addition series, which begins with 2 and adds 6.

Q 52. 9, 11, 33, 13, 15, 33, 17, … choose which pair of numbers comes next?
A) 19, 33
B) 33, 35
C) 33, 19
D) 15, 33
E) 19, 21

Solution:
In this alternating repetition series, a random number, 33, is interpolated every third number into a simple addition series, in which each number increases by 2.

Q 53. 2, 3, 4, 5, 6, 4, 8, … choose which pair of numbers comes next?
A) 9, 10
B) 4, 8
C) 10, 4
D) 9, 4
E) 8, 9

Solution:
This is an alternating addition series with a random number, 4, interpolated as every third number. In the main series, 1 is added, then 2 is added, then 1, then 2, and so on.

Q 54. 17, 17, 34, 20, 20, 31, 23, … choose which pair of numbers comes next?
A) 26, 23
B) 34, 20
C) 23, 33
D) 27, 28
E) 23, 28

Solution:
This is an alternating subtraction series with repetition. There are two different patterns here. In the first, a number repeats itself; then 3 is added to that number to arrive at the next number, which also repeats. This gives the series 17, 17, 20, 20, 23, and so on. Every third number follows a second pattern, in which 3 is subtracted from each number to arrive at the next: 34, 31, 28.

Q 55. 6, 20, 8, 14, 10, 8, 12, … choose which pair of numbers comes next?
A) 14, 10
B) 2, 18
C) 4, 12
D) 2, 14
E) 14, 14

Solution:
This is an alternating addition and subtraction series. In the first pattern, 2 is added to each number to arrive at the next; in the alternate pattern, 6 is subtracted from each number to arrive at the next.

Q 56. 21, 25, 18, 29, 33, 18, … choose which pair of numbers comes next?
A) 43, 18
B) 41, 44
C) 37, 18
D) 37, 41
E) 38, 41

Solution:
This is a simple addition series with a random number, 18, interpolated as every third number. In the series, 4 is added to each number except 18, to arrive at the next number.

Q 57. 75, 65, 85, 55, 45, 85, 35, … choose which pair of numbers comes next?
A) 25, 15
B) 25, 85
C) 35, 25
D) 85, 35
E) 25, 75

Solution:
This is a simple subtraction series in which a random number, 85, is interpolated as every third number. In the subtraction series, 10 is subtracted from each number to arrive at the next.

Q 58. 11, 16, 21, 26, 31, 36, 41, … choose which pair of numbers comes next?
A) 47, 52
B) 46, 52
C) 45, 49
D) 46, 51
E) 33, 38

Solution:
In this simple addition series, each number is 5 more than the previous number.

Q 59. 3, 8, 13, 18, 23, 28, 33, … choose which pair of numbers comes next?
A) 39, 44
B) 38, 44
C) 38, 43
D) 37, 42
E) 33, 38

Solution:
In this simple addition series, each number is 5 greater than the previous number.

Q 60. 84, 78, 72, 66, 60, 54, 48, … choose which pair of numbers comes next?
A) 44, 34
B) 42, 36
C) 42, 32
D) 40, 34
E) 38, 32

Solution:
In this simple subtraction series, each number is 6 less than the previous number.

Q 61. 20, 20, 17, 17, 14, 14, 11, … choose which pair of numbers comes next?
A) 8, 8
B) 11, 11
C) 11, 14
D) 8, 9
E) 11, 8

Solution:
This is a simple subtraction with repetition series. It begins with 20, which is repeated, then 3 is subtracted, resulting in 17, which is repeated, and so on.

Q 62. 61, 57, 50, 61, 43, 36, 61, … choose which pair of numbers comes next?
A) 29, 61
B) 27, 20
C) 31, 61
D) 22, 15
E) 29, 22

Solution:
This is an alternating repetition series, in which a random number, 61, is interpolated as every third number into an otherwise simple subtraction series. Starting with the second number, 57, each number (except 61) is 7 less than the previous number.

Q 63. 9, 12, 11, 14, 13, 16, 15, … choose which pair of numbers comes next?
A) 14, 13
B) 18, 21
C) 14, 17
D) 12, 13
E) 18, 17

Solution:
This is a simple alternating addition and subtraction series. First, 3 is added, then 1 is subtracted, then 3 is added, 1 subtracted, and so on.

Q 64. 4, 8, 22, 12, 16, 22, 20, 24, … choose which pair of numbers comes next?
A) 28, 32
B) 28, 22
C) 22, 28
D) 32, 36
E) 22, 26

Solution:
This is an alternating repetition series, with a random number, 22, interpolated as every third number into an otherwise simple addition series. In the addition series, 4 is added to each number to arrive at the next number.

Q 65. 40, 40, 31, 31, 22, 22, 13, … choose which pair of numbers comes next?
A) 13, 4
B) 13, 5
C) 4, 13
D) 9, 4
E) 4, 4

Solution:
This is a subtraction series with repetition. Each number repeats itself and then decreases by 9.

Q 66. 1, 10, 7, 20, 13, 30, 19, … choose which pair of numbers comes next?
A) 26, 40
B) 29, 36
C) 40, 25
D) 25, 31
E) 40, 50

Solution:
Here, every other number follows a different pattern. In the first series, 6 is added to each number to arrive at the next. In the second series, 10 is added to each number to arrive at the next.

Q 67. 10, 20, 25, 35, 40, 50, 55, … choose which pair of numbers comes next?
A) 70, 65
B) 60, 70
C) 60, 75
D) 60, 65
E) 65, 70

Solution:
This is an alternating addition series, in which 10 is added, then 5, then 10, and so on.

Q 68. 42, 40, 38, 35, 33, 31, 28, … choose which pair of numbers comes next?
A) 25, 22
B) 26, 23
C) 26, 24
D) 25, 23
E) 26, 22

Solution:
This is an alternating subtraction series in which 2 is subtracted twice, then 3 is subtracted once, then 2 is subtracted twice, and so on.

Q 69. 6, 10, 14, 18, 22, 26, 30, … choose which pair of numbers comes next?
A) 36, 40
B) 33, 37
C) 38, 42
D) 34, 36
E) 34, 38

Solution:
This simple addition series adds 4 to each number to arrive at the next.

Q 70. 8, 12, 9, 13, 10, 14, 11, … choose which pair of numbers comes next?
A) 14, 11
B) 15, 12
C) 8, 15
D) 15, 19
E) 8, 5