Logical Reasoning - Number Series - Discussion
Discussion Forum : Number Series - Type 1 (Q.No. 16)
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
16.
Look at this series: 80, 10, 70, 15, 60, ... What number should come next?
Answer: Option
Explanation:
This is an alternating addition and subtraction series. In the first pattern, 10 is subtracted from each number to arrive at the next. In the second, 5 is added to each number to arrive at the next.
Discussion:
83 comments Page 5 of 9.
Abhiram said:
9 years ago
Thank you all for explaining this.
Neha said:
9 years ago
80,_70_60_50_(decrease series.) in 10 table.
10 15 20 25( increase series) in 5 table.
10 15 20 25( increase series) in 5 table.
Mannu kumar said:
9 years ago
80-10=70
70-10=60
60-10=50 and so on...
NW
10+5=15
15+5=20
20+5=25 and so on.
Now your final series is 80, 10, 70, 15, 60, 20, 50, 25.
70-10=60
60-10=50 and so on...
NW
10+5=15
15+5=20
20+5=25 and so on.
Now your final series is 80, 10, 70, 15, 60, 20, 50, 25.
Disha said:
9 years ago
Thanks for explaining the solution.
Ria sen said:
9 years ago
Need more explanation.
Chirag modi said:
9 years ago
Now, I understand this, Thank you all.
Nandini said:
9 years ago
Thanks for explaining the logic to find the answer. It's really helpful.
Shadab Akhtar said:
9 years ago
First series;
80 - 70 = 10.
10 + 60 = 70.
70 - 55 = 15.
15 + 45 = 60.
60 - 40 = 20.
And, alternate series;
-70 + 60 = -10.
+60 - 55 = +5.
-55 + 45 = -10.
+45 - 40 = +5 and so on....
Hope this answer clarify all your doubt.
80 - 70 = 10.
10 + 60 = 70.
70 - 55 = 15.
15 + 45 = 60.
60 - 40 = 20.
And, alternate series;
-70 + 60 = -10.
+60 - 55 = +5.
-55 + 45 = -10.
+45 - 40 = +5 and so on....
Hope this answer clarify all your doubt.
DANISH said:
9 years ago
But both options 50 and 20 are there so which one to choose?
Roshan Roy said:
9 years ago
In this series they have divided numbers into two parts .This series goes like this 80, 10, 70, 15, 60, 20, 50, 25, 40, 30, 30, 35, 20 40, 10, 45 ...
80 70 60 50 -----> Decrement of 10.
10 15 20 25 -----> Increment of 5.
80 70 60 50 -----> Decrement of 10.
10 15 20 25 -----> Increment of 5.
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers