Logical Reasoning - Number Series - Discussion
Discussion Forum : Number Series - Type 1 (Q.No. 6)
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
6.
Look at this series: 21, 9, 21, 11, 21, 13, 21, ... What number should come next?
Answer: Option
Explanation:
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.
Discussion:
45 comments Page 2 of 5.
Eerappa said:
7 years ago
The second digit is 9,
4th digit is 11.
so alternatively adding two numbers,
after 3 the next is 15.
9,11,13,15..
4th digit is 11.
so alternatively adding two numbers,
after 3 the next is 15.
9,11,13,15..
(4)
Muzaan ul aazeem said:
8 years ago
Adding and subtracting both we can use in descending or ascending.
Rajini arunkumar said:
8 years ago
21-12 = 9
9+12 = 21
21-10 = 11
11+10 = 21
21-8 = 13
13+8 = 21
21-6 = 15.
Why substracting 6 means, they subtracting adding like 10,8 so next even no.is 6 only.
9+12 = 21
21-10 = 11
11+10 = 21
21-8 = 13
13+8 = 21
21-6 = 15.
Why substracting 6 means, they subtracting adding like 10,8 so next even no.is 6 only.
(1)
Swarnendu said:
9 years ago
21 remains interpolated and 2 is added to the number.
Jhansi said:
9 years ago
Logic : 21 becomes constant and alternate number should add 2.
M.RAGHURAM PGDM 1 said:
9 years ago
Take 21 alternatively and add 2 so, the answer is 15.
Shivam said:
9 years ago
You see that the series is,
21 - 9 = 12.
Again after 9 have 21.
Again you see 2,
And again 21 - 9.
You see that 10, 10, 8, 8, 6, 6 series has follows.
21 - 9 = 12.
Again after 9 have 21.
Again you see 2,
And again 21 - 9.
You see that 10, 10, 8, 8, 6, 6 series has follows.
Abhay ide said:
9 years ago
By adding the given numbers.
21 + 9 = 30.
21 + 11 = 32.
21 + 13 = 34.
21 + 15 = 36.
This increased by 2 numbers.
21 + 9 = 30.
21 + 11 = 32.
21 + 13 = 34.
21 + 15 = 36.
This increased by 2 numbers.
Sheenam said:
10 years ago
Yes, 11 + 2 = 13.
13 + 2 = 15.
This is very easy question but my according this question is very confused.
13 + 2 = 15.
This is very easy question but my according this question is very confused.
Alisha said:
10 years ago
21+0 = 21, 9+2 = 11, 21+0 = 21, 11+2 = 13, 21+0 = 21, 13+2 = 15.
Answer: 15.
Answer: 15.
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