Logical Reasoning - Number Series - Discussion
Discussion Forum : Number Series - Type 1 (Q.No. 10)
Directions to Solve
In each series, look for the degree and direction of change between the numbers. In other words, do the numbers increase or decrease, and by how much
10.
Look at this series: 31, 29, 24, 22, 17, ... What number should come next?
Answer: Option
Explanation:
This is a simple alternating subtraction series, which subtracts 2, then 5.
Discussion:
40 comments Page 2 of 4.
Dr dhaniram said:
9 years ago
31 - 2 = 29.
29 - 5 = 24.
24 - 2 = 22.
22 - 5 = 17.
17 - 2 = 15.
So the missing term is 15.
29 - 5 = 24.
24 - 2 = 22.
22 - 5 = 17.
17 - 2 = 15.
So the missing term is 15.
(1)
Surya said:
6 years ago
2 is the difference of first two digits.
5 is the difference second and third digit.
So the series follows 2,5, 2,5,2...
17-2 = 15.
5 is the difference second and third digit.
So the series follows 2,5, 2,5,2...
17-2 = 15.
(1)
John JM said:
6 years ago
31-29=2.
29-24=5.
24-22=2.
17-12=5.
So the answer is 12.
29-24=5.
24-22=2.
17-12=5.
So the answer is 12.
(1)
Pradeepkumar said:
7 years ago
31-2=29,
29-5=24,
24-2=22,
22-5=17,
17-2=15,
15 is the answer.
29-5=24,
24-2=22,
22-5=17,
17-2=15,
15 is the answer.
(1)
Mohit said:
8 years ago
I thought it would work as the difference of 6.
31, 29,24,22,17.
Difference between :- 31-24:-6
29-22:-6
24-17:-6
Now next number in series would be 22-15:-6, therefore, 15 would be the answer.
31, 29,24,22,17.
Difference between :- 31-24:-6
29-22:-6
24-17:-6
Now next number in series would be 22-15:-6, therefore, 15 would be the answer.
Mohan said:
8 years ago
Here,
31-29=2.
29-24=5.
So the difference is 2,5,2,5.
So, next it should be 17-2=15 so it is the answer.
31-29=2.
29-24=5.
So the difference is 2,5,2,5.
So, next it should be 17-2=15 so it is the answer.
Prasanth.E said:
8 years ago
31,29,24,22,17.
Total series=5;
29+7=22
22+7=15.
So, the difference is odd=7, second number, fourth number is considered.
Total series=5;
29+7=22
22+7=15.
So, the difference is odd=7, second number, fourth number is considered.
Sruthi said:
8 years ago
31-29=2.
29-24=5.
So diff are 2,5,2,5.
Hence 15 should be the answer to get a difference of 5.
29-24=5.
So diff are 2,5,2,5.
Hence 15 should be the answer to get a difference of 5.
Ishita said:
7 years ago
31-2 = 29
29-5 = 24
24-2 = 22
22-5 = 17
17-2 = 15.
15 is the answer.
29-5 = 24
24-2 = 22
22-5 = 17
17-2 = 15.
15 is the answer.
Palwasha said:
3 years ago
Thanks all for explaining the answer.
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