# 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

Therefore, the answer is 430.

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
[show_answer]Answer: Option DQ 18. 9, 27, 31, 155, 161, 1127, ?

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
[show_answer]Answer: Option ASolution: Sunday to Monday = no gap
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