2, 15, 4, 12, 6, 7, ?, ?
A) 8,8
B) 8,0
C) 3,8
D) NONE OF THESE
Answers
Answer :
B) 8,0
Step-by-step explanation:
There are two sequences in these arrangement : 2,15,4,12,6,7….
Let’s separate them: 2,4,6…… and 15,12,7…..
First sequence (2,4,6……) increasing by 2 as common difference therefore 8 is the next number.
Second sequence(15,12,7…..) decreasing by increasing common difference i.e common difference increasing by 2 . Increasing common differences therefore are 3,5….next common difference is 7 and next number is 7–7=0
The next two numbers are 8 and 0
Answer 2,15,4,12,6,7,8,0
The series 2,15,4,12,6,7....
so by considering alternates as one series i.e., 2,4,6,....
and 15,12,7,....
so, now by observing 1st series there are with the difference 2 the next number can be 8.
In the 2nd series the difference between 1st and second numbers are 3 and difference between second and third is 5 i.e., 3+2(3 is the previous numbers difference 2 is the common difference in the first series) and the next difference should be 5+2=7 so the next number would be 0.
now the series is as follows 2,15,4,12,6,7,8,0
It is a double series.
The first series 2,4,6,?
The second series is 15,12,7,?
The first series is incremented by 2 while the second series is decremented by 3, 5 and so on with eqch term that is used to decrement being incremented by 2(Another way to consider is the term being decremented by one more than the previous term 15 being decremented by 1+2 12 being decremented by 1+4 and so on) .
So the first series becomes 2,4,6,8 and the second one becomes 15,12,7,0
So it becomes 2,15,4,12,6,7,8,0