Verbal Reasoning - Series Completion - Discussion
Discussion Forum : Series Completion - Section 1 (Q.No. 9)
Directions to Solve
Choose the correct alternative that will continue the same pattern and replace the question mark in the given series.
9.
5, 6, 9, 15, ?, 40
Answer: Option
Explanation:
The pattern is + 1, + 3, + 6,....., i.e. + 1, + (1 + 2), + (1 + 2 + 3),.....
So, missing term = 15 + (1 + 2 + 3 + 4) = 25.
Discussion:
15 comments Page 1 of 2.
Shubham gour said:
4 years ago
5 + 1 = 6.
6 + (1+2) = 9.
9 + (1+2+3) = 15.
15 + (1+2+3+4) = 25.
25 + (1+2+3+4+5) = 40.
6 + (1+2) = 9.
9 + (1+2+3) = 15.
15 + (1+2+3+4) = 25.
25 + (1+2+3+4+5) = 40.
(34)
Maryam said:
7 years ago
The sequence I was following.
(5*2)-4.
(6*2)-3.
(9*2)-2.
But
(15*2)-1 =29 (the pattern is same from above, the answer only changes in the last step).
(5*2)-4.
(6*2)-3.
(9*2)-2.
But
(15*2)-1 =29 (the pattern is same from above, the answer only changes in the last step).
(2)
Sai krishna said:
7 years ago
You are right, agree @Jitender.
Biplab said:
8 years ago
5 9 ? =(15+25)
6 15 40
cross adding between 9+6=15 so 15 +25=40.
6 15 40
cross adding between 9+6=15 so 15 +25=40.
(1)
Naveen Kumar said:
8 years ago
I agree with your explanations @Venuu and @Jitender.
(1)
Venuu said:
8 years ago
You should add there positions respectively.
5, 6, 9, 15_40.
1) 5+1=6.
2) 6+2+1=9.
3) 9+3+2+1=15.
4) 15+4+3+2+1=25.
5) 25+5+4+3+2+1=40.
5, 6, 9, 15_40.
1) 5+1=6.
2) 6+2+1=9.
3) 9+3+2+1=15.
4) 15+4+3+2+1=25.
5) 25+5+4+3+2+1=40.
(1)
Bhanu said:
8 years ago
Can anyone explain clearly?
Ramya said:
9 years ago
Differences between first four numbers in series are 1, 3, 6.
1*1 + 2 = 3.
3*1 + 3 = 6.
So.
6*1 + 4 = 10.
The next number is 10 + 15 = 25.
1*1 + 2 = 3.
3*1 + 3 = 6.
So.
6*1 + 4 = 10.
The next number is 10 + 15 = 25.
Abhishek said:
1 decade ago
Ignore first number (5), now 6+9=15, 15+25=40.
Wesley said:
1 decade ago
5+1 = 6.
6+(1+2) = 9.
9+(1+2+3) = 15.
15+(1+2+3+4) = 25.
25+(1+2+3+4+5) = 40.
6+(1+2) = 9.
9+(1+2+3) = 15.
15+(1+2+3+4) = 25.
25+(1+2+3+4+5) = 40.
(1)
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