Verbal Reasoning - Series Completion - Discussion

Choose the correct alternative that will continue the same pattern and replace the question mark in the given series.

5. 

125,80,45,20,?

[A]. 5
[B]. 8
[C]. 10
[D]. 12

Answer: Option A

Explanation:

The pattern is - 45, - 35, - 25, .....

So, missing term = 20 - 15 = 5.


Krishna Kumar said: (May 10, 2011)  
Another method :
5*5^2 => 5*25=125
5*4^2 => 5*16=80
5*3^2 => 5*9=45
5*2^2 => 5*4=20
so the next term would be...
5*1^2 => 5*1=5
Hence the next term is obtained as 5.

Sigamani said: (Jun 13, 2011)  
Sigamani,

It is a very and easy calcuation method, Thank you.

Vishnu said: (Jul 8, 2011)  
Very simple method:

Difference between 125-80=45

80-45=35
45-20=25
so 20-15=5

Nishritha said: (Aug 16, 2011)  
All are divisible by 5

125/5=25
80/5=16
45/5=9
20/5=4
25-16=9
9-4=5
5 is the answer

Divya said: (Sep 14, 2011)  
Thank you Vishnu.

It is very easy calculation method.

Naro said: (Jun 28, 2012)  
25*5=125.

20*4=80.

15*3=45.

10*2=20.

5*1=5.

First number is decreasing by 5 and second number is decreasing by 1.

Sai Ram said: (Jun 30, 2012)  
Here alternatives 125-45 = 80.
80-20 = 60.
So 45-40 = 5.

Deepak said: (Jul 17, 2013)  
5*5*5=125.
4*4*5=80.
3*3*5=45.
2*2*5=20.
1*1*5=5.

Ankit Mahale said: (Jun 24, 2014)  
5*5^2 = 125.
5*4^2 = 80.
5*3^2 = 45.
5*2^2 = 20.
5*1^2 = 5.

B.Manikanta said: (Aug 23, 2014)  
125/5, 80/5, 45/5, 20/5, (5/5).

25, 16, 9, 4, 1.

5, 4, 3, 2, 1.

So, the answer is 5.

Srinu said: (Jun 18, 2015)  
Thanks for all.

Mayank said: (Jun 26, 2015)  
Here,

125-80=45.
80-45=35.
35-20=15.
20-15=5.

All of the no are difference between the only for 10 after 10.

Edddd said: (Jul 28, 2015)  
Select the option for that continues the pattern in each question 3, -6, 12, 4, 20?

Nrusingha said: (Jan 21, 2016)  
Some one already told this method above, & is a short cut,

25*5 --> 5^2 * 5.

16*5 --> 4^2 * 5.

9*5 --> 3^2 * 5.

4*5 --> 2^2 * 5.

1*5 --> 1^2 * 5 (answer).

Remaining methods are boring to me.

Mozako said: (Jun 28, 2018)  
10^2 + 5^2 = 125.
8^2 + 4^2 = 80.
6^2 + 3^2 = 45.
4^2 + 2^2 = 20.
2^2 + 1^2 = 5.

Divya said: (Sep 1, 2020)  
125 - 80 = 45,
80 - 45 = 35,
45 - 20 = 25.

So the next difference should be of 15.
20-15 = 5 answer.

Khapa said: (May 26, 2021)  
According to me,

It's;
125-45 = 80
80-35 = 45
45-25 = 20
20-15 = 5.

So, 5 is the answer.

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