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 1 of 9.
Aniket Das said:
12 months ago
Question: 80, 10, 70, 15, 60.
Look 80, 70 and 60 they are all decreasing by 10.
Whereas 10, 15 is increasing by 5.
So we get the series.
First 10 then we get 15 and then 15+5 comes 20.
It's like taking the alternate numbers (leaving one).
Hope this helps.
Look 80, 70 and 60 they are all decreasing by 10.
Whereas 10, 15 is increasing by 5.
So we get the series.
First 10 then we get 15 and then 15+5 comes 20.
It's like taking the alternate numbers (leaving one).
Hope this helps.
(24)
Prince Bhanu said:
2 years ago
@Kitana.
80,10,70,15,60,-?
Here 10 will be subtracted,
80 - 10 = 70
70 - 10 = 60.
For the remaining, 5 will be adding 10 + 5 = 15.
So, 15+5 = 20!
So the answer is 20.
80,10,70,15,60,-?
Here 10 will be subtracted,
80 - 10 = 70
70 - 10 = 60.
For the remaining, 5 will be adding 10 + 5 = 15.
So, 15+5 = 20!
So the answer is 20.
(17)
A SANTHI said:
3 years ago
@All
Here is the logic;
1st set is 80 70 60 here if we add and subtract 10 from the middle number 70 we will get 80 and 60 series.
The 2nd set is 10 15 and x it is same as the above but here we have 5 to add and subtract from the middle number 15 if we do so we will get 10 and 20 respectively.
Here is the logic;
1st set is 80 70 60 here if we add and subtract 10 from the middle number 70 we will get 80 and 60 series.
The 2nd set is 10 15 and x it is same as the above but here we have 5 to add and subtract from the middle number 15 if we do so we will get 10 and 20 respectively.
(15)
Ruqaiya said:
3 years ago
80, 10, 70, 15, 60,
You have to add differences.
80-10=70,
10-70=60,
70-15=55,
15-60=45.
Double differences.
70-60=10,
60-55=5,
55-45=10.
So next no is 5.
45 - 5 = 40.
40 - 60 = 20.
You have to add differences.
80-10=70,
10-70=60,
70-15=55,
15-60=45.
Double differences.
70-60=10,
60-55=5,
55-45=10.
So next no is 5.
45 - 5 = 40.
40 - 60 = 20.
(15)
Talha said:
2 years ago
80, 10, 70, 15, 60, 20.
Explanation;
Differences Between Them.
(-70+60-55+45-40).
Because the difference is (-10-5+10-5).
So; (45-5=40 Then 60-40=20).
Answer = 20.
Explanation;
Differences Between Them.
(-70+60-55+45-40).
Because the difference is (-10-5+10-5).
So; (45-5=40 Then 60-40=20).
Answer = 20.
(12)
Irisha singh said:
11 months ago
Let's see the sequence of 80, 70 and 60 there's reduced by 10 and in another sequence of 10, 15 there's an additional of 5.
So the answer is 20.
So the answer is 20.
(10)
Divya said:
3 years ago
See the question in two halves in first it is given 80 -10 = 70.
70 -10 = 60.
In the second half it is given 10 + 5 = 15.
Now the answer is given in the second halves
So, the answer will be 15+5= 20.
70 -10 = 60.
In the second half it is given 10 + 5 = 15.
Now the answer is given in the second halves
So, the answer will be 15+5= 20.
(10)
Swapna said:
2 years ago
The series like {a1,b1,a2,b2,a3,.......}
Here
a2 = a1 - 10;
b2 = b1 + 5;
b4 = b3 + 5 i.e 15+5=20.
Here
a2 = a1 - 10;
b2 = b1 + 5;
b4 = b3 + 5 i.e 15+5=20.
(8)
Kitana said:
3 years ago
Can anyone, explain me clearly?
(7)
Sai said:
12 months ago
Firstly focus on.
80, 70, 60, (series are decreased by number (-10))
10, 15, _? (Series are increased by (+5))
So after the number is;
(10)+5(15)+5(20)<-->
So, 20 is the answer .
The Final answer is;
80, 10, 70, 15, 60, 20........
80, 70, 60, (series are decreased by number (-10))
10, 15, _? (Series are increased by (+5))
So after the number is;
(10)+5(15)+5(20)<-->
So, 20 is the answer .
The Final answer is;
80, 10, 70, 15, 60, 20........
(3)
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