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All questions of Series for OPSC OCS (Odisha) Exam
Look at this series: 8, 6, 9, 23, 87 , ... What number should come next?- a)128
- b)226
- c)324
- d)429
Correct answer is 'D'. Can you explain this answer?
a)
128
b)
226
c)
324
d)
429
 | Meghana Kaur answered |
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
6 x 2 - 3 = 9
9 x 3 - 4 = 23
23 x 4 - 5 = 87
87 x 5 - 6 = 429
Look at this series: 4, 9, 19, 39, 79,... What number should come next?- a)169
- b)159
- c)119
- d)139
Correct answer is option 'B'. Can you explain this answer?
a)
169
b)
159
c)
119
d)
139
 | Anjali Gupta answered |
The pattern is
4*2+1=9
9*2+1=19
19*2+1=39
39*2+1=79
79*2+1=159
4*2+1=9
9*2+1=19
19*2+1=39
39*2+1=79
79*2+1=159
Look at this series: 201, 202, 204, 207, ... What number should come next?- a)205
- b)208
- c)210
- d)211
Correct answer is option 'D'. Can you explain this answer?
a)
205
b)
208
c)
210
d)
211
 | Nandini Iyer answered |
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.
Find the missing number.17, 19, 23, 29, 31, 37, _____- a)47
- b)43
- c)40
- d)41
Correct answer is option 'D'. Can you explain this answer?
Find the missing number.
17, 19, 23, 29, 31, 37, _____
a)
47
b)
43
c)
40
d)
41
 | Shruti Dey answered |
The given numbers are consecutive prime numbers in increasing order starting with 17.
Hence, the next number in the series is 41.
Hence, the next number in the series is 41.
0, 4, 18, 48, ___, 180- a)58
- b)144
- c)84
- d)100
Correct answer is option 'D'. Can you explain this answer?
0, 4, 18, 48, ___, 180
a)
58
b)
144
c)
84
d)
100
 | Lavanya Menon answered |
1st term = 5
2nd term = 5 × 2 + 3 = 13
3rd term = 13 × 3 + 2 = 41
4th term = 41 × 2 + 3 = 85
5th term = 85 × 3 + 2 =257...
2nd term = 5 × 2 + 3 = 13
3rd term = 13 × 3 + 2 = 41
4th term = 41 × 2 + 3 = 85
5th term = 85 × 3 + 2 =257...
⇒ For every term at even position, the previous term is multiplied by 2 and 3 is added.
⇒ For every term at odd position, the previous term is multiplied by 3 and 2 is added.
⇒ For every term at odd position, the previous term is multiplied by 3 and 2 is added.
So the missing term is: 257 × 2 + 3 = 517
Look at this series: 2, 6, 18, 54, ... What number should come next?- a)108
- b)148
- c)162
- d)216
Correct answer is option 'C'. Can you explain this answer?
a)
108
b)
148
c)
162
d)
216
| | Aisha Gupta answered |
CORRECT OPTION IS (C)
This is a simple multiplication series. Each number is 3 times more than the previous number.
This is a simple multiplication series. Each number is 3 times more than the previous number.
Look at this series: 5.2, 4.8, 4.4, 4, ... What number should come next?- a)3
- b)3.3
- c)3.5
- d)3.6
Correct answer is option 'D'. Can you explain this answer?
a)
3
b)
3.3
c)
3.5
d)
3.6
 | Rajat Patel answered |
In this simple subtraction series, each number decreases by 0.4.
17, __, 65, 113, 129, 161, 209.- a)34
- b)33
- c)40
- d)44
Correct answer is option 'B'. Can you explain this answer?
17, __, 65, 113, 129, 161, 209.
a)
34
b)
33
c)
40
d)
44
 | Shalini Patel answered |
1st term = 8
2nd term = 8 x 2 = 16
3rd term = 16 x 3 = 48
4th term = 48 x 2 = 96
5th term = 96 x 3 = 288
6th term = 288 x 2 = 576...
2nd term = 8 x 2 = 16
3rd term = 16 x 3 = 48
4th term = 48 x 2 = 96
5th term = 96 x 3 = 288
6th term = 288 x 2 = 576...
⇒ For every term at even position, the previous term is multiplied by 2.
⇒ For every term at odd position, the previous term is multiplied by 3.
⇒ For every term at odd position, the previous term is multiplied by 3.
So the missing term is: 576 × 3 = 1728
Look at this series: 14, 28, 20, 40, 32, 64, ... What number should come next?- a)52
- b)56
- c)92
- d)128
Correct answer is option 'B'. Can you explain this answer?
a)
52
b)
56
c)
92
d)
128
| | Anjali Gupta answered |
The series is 14, 28, 20, 40, 32, 64
Take three terms at a time. The notation be as follows:-
Let, First term = a = 14
It is evident that Second term= 2*a = 2 * 14 = 28 and,
The Third term = Second term - 8 OR ( 2*a - 8 ) = 28 - 8 = 20
Now consider the third, fourth and the fifth term.
Let, Third term = a = 20
It is evident that Fourth term= 2*a = 2 * 20 = 40 and,
The Fifth term = Second term - 8 OR ( 2*a - 8 ) = 40 - 8 = 32
Similarly consider fifth, sixth and the seventh(term to be found).
Let, Fifth term = a = 32
It is evident that Sixth term = 2*a = 2 * 32 = 64 and,
The Seventh term ( term to calculated) = Second term - 8 OR ( 2*a - 8 ) = 64 - 8 = 56
Take three terms at a time. The notation be as follows:-
Let, First term = a = 14
It is evident that Second term= 2*a = 2 * 14 = 28 and,
The Third term = Second term - 8 OR ( 2*a - 8 ) = 28 - 8 = 20
Now consider the third, fourth and the fifth term.
Let, Third term = a = 20
It is evident that Fourth term= 2*a = 2 * 20 = 40 and,
The Fifth term = Second term - 8 OR ( 2*a - 8 ) = 40 - 8 = 32
Similarly consider fifth, sixth and the seventh(term to be found).
Let, Fifth term = a = 32
It is evident that Sixth term = 2*a = 2 * 32 = 64 and,
The Seventh term ( term to calculated) = Second term - 8 OR ( 2*a - 8 ) = 64 - 8 = 56
Look at this series: 544, 509, 474, 439, ... What number should come next?- a)404
- b)414
- c)420
- d)445
Correct answer is option 'A'. Can you explain this answer?
a)
404
b)
414
c)
420
d)
445
 | Bijoy Pillai answered |
Your answer is Option A: 404
In each number, you decrease 35, thus 404 is the right answer.
12000, 2395, 474, 89.8, ___.- a)17.96
- b)12.96
- c)22.96
- d)none of these
Correct answer is option 'B'. Can you explain this answer?
12000, 2395, 474, 89.8, ___.
a)
17.96
b)
12.96
c)
22.96
d)
none of these
 | Vikas Kapoor answered |
The given numbers are squares of consecutive natural numbers in decreasing order starting with 15,
i.e., the numbers 225, 196, 169, ____, 100, 81 can be written as 152, 142, 132 , ____, 112 , 102 , 92.
i.e., the numbers 225, 196, 169, ____, 100, 81 can be written as 152, 142, 132 , ____, 112 , 102 , 92.
Hence, the missing number is 122 = 144.
Look at this series: 2, 4, 6, 8, 10, ... What number should come next?- a)11
- b)12
- c)13
- d)14
Correct answer is option 'B'. Can you explain this answer?
Look at this series: 2, 4, 6, 8, 10, ... What number should come next?
a)
11
b)
12
c)
13
d)
14
| | Kiran Reddy answered |
Each number increases by 2.
Like -
First number is 2
Second number = 2 + 2 =4
Third number = 4 + 2 = 6
Fourth number = 6 + 2 = 8
Fifth number = 8 + 2 = 10 and
Sixth number = 10 + 2 = 12
Hence, The answer is (b) 12.
Like -
First number is 2
Second number = 2 + 2 =4
Third number = 4 + 2 = 6
Fourth number = 6 + 2 = 8
Fifth number = 8 + 2 = 10 and
Sixth number = 10 + 2 = 12
Hence, The answer is (b) 12.
100, 70, 46, 28, __, 10- a)17
- b)15
- c)20
- d)16
Correct answer is option 'D'. Can you explain this answer?
100, 70, 46, 28, __, 10
a)
17
b)
15
c)
20
d)
16
| | Vivek Patel answered |
1st term = 75
2nd term = 75 + 216 = 75 + 63 = 291
3rd term = 291 + 125 = 291 + 53 = 416
4th term = 416 + 64 = 416 + 43 = 480
5th term = 480 + 27 = 480 + 33 = 507...
2nd term = 75 + 216 = 75 + 63 = 291
3rd term = 291 + 125 = 291 + 53 = 416
4th term = 416 + 64 = 416 + 43 = 480
5th term = 480 + 27 = 480 + 33 = 507...
The differences are cubes of consecutive natural numbers in decreasing order from 6.
So, the missing term = 507 + 8 = 507 + 23 = 515
So, the missing term = 507 + 8 = 507 + 23 = 515
Look at this series: 80, 10, 70, 15, 60, ... What number should come next?- a)20
- b)25
- c)30
- d)50
Correct answer is 'A'. Can you explain this answer?
a)
20
b)
25
c)
30
d)
50
| | Varun Kapoor answered |
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.
1, 8, 28, 99, 412, 2075, ____.- a)12450
- b)12462
- c)10387
- d)10375
Correct answer is option 'B'. Can you explain this answer?
1, 8, 28, 99, 412, 2075, ____.
a)
12450
b)
12462
c)
10387
d)
10375
| | Lavanya Menon answered |
The 1st to 5th terms are 0, 5, 22, 57, 116.
These terms are 1 – 1, 8 – 3, 27 – 5, 64 – 7, 125 – 9.
i.e. 13 – 1, 23 – 3, 33 – 5, 43 – 7, 53 – 9
These terms are 1 – 1, 8 – 3, 27 – 5, 64 – 7, 125 – 9.
i.e. 13 – 1, 23 – 3, 33 – 5, 43 – 7, 53 – 9
So, the nth term of the series: n3 – (2n – 1).
So, the 6th term of the series is 63 – (2 × 6 –1) = 216 – 11 = 205.
Look at this series: 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
Correct answer is option 'C'. Can you explain this answer?
a)
4.2
b)
4.4
c)
4.7
d)
5.1
| | Alok Mehta answered |
In this simple addition series, each number increases by 0.8.
Rule = (1st no.) (1st no. + 0.8 = 2nd no.) (2nd no. + 0.8 = 3rd number)...
Now (1.5) (1.5 + 0.8 = 2.3) (2.3 + 0.8 = 3.1) (3.1 + 0.8 = 3.9) (3.9 + 0.8 = 4.7)...
So the anwser is c = 4.7
7, 9, 13, 21, 37, ____- a)58
- b)63
- c)69
- d)72
Correct answer is option 'C'. Can you explain this answer?
7, 9, 13, 21, 37, ____
a)
58
b)
63
c)
69
d)
72
| | Lavanya Menon answered |
The common difference between consecutive terms is 6, 12, 6, 12 & so on. So, the term next to 141 is 141 + 6 = 147
1, 2, 8, 33, 148, __.- a)265
- b)465
- c)565
- d)765
Correct answer is option 'D'. Can you explain this answer?
1, 2, 8, 33, 148, __.
a)
265
b)
465
c)
565
d)
765
 | Ankit Saini answered |
1*1 + (1)2 = 1+1 = 2
2*2 + (2)2 = 4+4 = 8
8*3 + (3)2 = 24+9 = 33
33*4 + (4)2 = 132+16 = 148
148*5 + (5)2 =740+25 = 765
2*2 + (2)2 = 4+4 = 8
8*3 + (3)2 = 24+9 = 33
33*4 + (4)2 = 132+16 = 148
148*5 + (5)2 =740+25 = 765
97, 83, 73, 67, 59, _____- a)53
- b)49
- c)52
- d)47
Correct answer is option 'D'. Can you explain this answer?
97, 83, 73, 67, 59, _____
a)
53
b)
49
c)
52
d)
47
 | Naveen Chakraborty answered |
Understanding the Sequence
The given sequence is:
- 97, 83, 73, 67, 59, _____
To find the missing number, we need to identify the pattern in the sequence.
Identifying the Differences
Let's calculate the differences between consecutive numbers:
- 97 - 83 = 14
- 83 - 73 = 10
- 73 - 67 = 6
- 67 - 59 = 8
The differences are as follows:
- 14, 10, 6, 8
Finding the Pattern in Differences
The differences do not form a simple arithmetic sequence, but we can observe:
- The first difference (14) decreases by 4 to give the second difference (10).
- The second difference (10) decreases by 4 to give the third difference (6).
- The fourth difference (from 67 to 59) shows an increase, but importantly, it hints at a trend.
If we hypothesize that the next difference might continue this pattern, we could assume that the gap changes might stabilize around a certain difference.
Calculating the Next Number
Following the observed pattern, we can guess the next difference might be around 12 or stay close to previous differences. Thus:
- If we subtract a difference of 12 from 59, we get:
59 - 12 = 47
Conclusion
By analyzing the sequence and the pattern of differences, we conclude that the missing number is:
Option D: 47
This is consistent with the observed fluctuations within the sequence.
The given sequence is:
- 97, 83, 73, 67, 59, _____
To find the missing number, we need to identify the pattern in the sequence.
Identifying the Differences
Let's calculate the differences between consecutive numbers:
- 97 - 83 = 14
- 83 - 73 = 10
- 73 - 67 = 6
- 67 - 59 = 8
The differences are as follows:
- 14, 10, 6, 8
Finding the Pattern in Differences
The differences do not form a simple arithmetic sequence, but we can observe:
- The first difference (14) decreases by 4 to give the second difference (10).
- The second difference (10) decreases by 4 to give the third difference (6).
- The fourth difference (from 67 to 59) shows an increase, but importantly, it hints at a trend.
If we hypothesize that the next difference might continue this pattern, we could assume that the gap changes might stabilize around a certain difference.
Calculating the Next Number
Following the observed pattern, we can guess the next difference might be around 12 or stay close to previous differences. Thus:
- If we subtract a difference of 12 from 59, we get:
59 - 12 = 47
Conclusion
By analyzing the sequence and the pattern of differences, we conclude that the missing number is:
Option D: 47
This is consistent with the observed fluctuations within the sequence.
8, 24, 12, ___, 18, 54- a)28
- b)36
- c)46
- d)38
Correct answer is option 'B'. Can you explain this answer?
8, 24, 12, ___, 18, 54
a)
28
b)
36
c)
46
d)
38
 | Abhiram Mehta answered |
So, term is 12*3 = 36.
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