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 5 of 5.
Akhilesh said:
1 decade ago
It is solved by another way i.e.
remove all alternate 21 and get differences between rest nos.
We'll get right answer i.e. B.
remove all alternate 21 and get differences between rest nos.
We'll get right answer i.e. B.
Vivek srivastava said:
1 decade ago
It is difference of number are 2
so
21-9=12
21-11=10
21-13=8
and
12-2=10
10-2=8
8-2=6
so
21-6=15
This is the right answer solved by vivek Srivastava.
so
21-9=12
21-11=10
21-13=8
and
12-2=10
10-2=8
8-2=6
so
21-6=15
This is the right answer solved by vivek Srivastava.
Saroj said:
1 decade ago
It is done in another way i.e..
by using decreasing order
11-9=2
13-11=2
15-13=2
so decrees the 2
by using decreasing order
11-9=2
13-11=2
15-13=2
so decrees the 2
CHINNA...IIIT said:
1 decade ago
*It is done in another way i.e..
by using decreasing order
21-12=9
21-10=11
21-8=13
21-6=15
so, decrease the subtract number to one by one..2
by using decreasing order
21-12=9
21-10=11
21-8=13
21-6=15
so, decrease the subtract number to one by one..2
(3)
Malkeet singh said:
1 decade ago
Another method:
21 is coming after every different number.
If we add 2 with every different number in ascending order automatic give the result.
For example:
different no. 9+2=11
different no. 11+2=13
different no. 13+2=15 and so on.
21 is coming after every different number.
If we add 2 with every different number in ascending order automatic give the result.
For example:
different no. 9+2=11
different no. 11+2=13
different no. 13+2=15 and so on.
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