Aptitude - Average - Discussion
Discussion Forum : Average - General Questions (Q.No. 4)
4.
The average of 20 numbers is zero. Of them, at the most, how many may be greater than zero?
Answer: Option
Explanation:
Average of 20 numbers = 0.
Sum of 20 numbers (0 x 20) = 0.
It is quite possible that 19 of these numbers may be positive and if their sum is a then 20th number is (-a).
Discussion:
135 comments Page 7 of 14.
PRABHAT KR.SINGH said:
9 years ago
19 will be appropriate answer.
Because in the question, it is mention that maximum number greater than zero.
If we take all positive number then sum will never be 0.
So, at least one number should be taken negative that should be equal to the sum of the 19 numbers.
So, (1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1+ 1) + (-19) /20.
I hope you got it.
Because in the question, it is mention that maximum number greater than zero.
If we take all positive number then sum will never be 0.
So, at least one number should be taken negative that should be equal to the sum of the 19 numbers.
So, (1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1+ 1) + (-19) /20.
I hope you got it.
Hemavathi said:
9 years ago
To get a value zero we can use,
(Sum of 19 positive numbers) - (-Value of sum)/(Sum of 18 positive numbers) - (Value of sum),
Here, the maximum probability of positive number is 19 (at most),
So the answer is 19.
(Sum of 19 positive numbers) - (-Value of sum)/(Sum of 18 positive numbers) - (Value of sum),
Here, the maximum probability of positive number is 19 (at most),
So the answer is 19.
Shivu said:
9 years ago
@Prabhat.
Your explanation was good, I got it now. Thank you.
Your explanation was good, I got it now. Thank you.
Divya said:
9 years ago
Is there any shortcut to find the answer for this question?
Kumar said:
9 years ago
Thanks for all of your explanations.
Amin Ullah said:
9 years ago
While the actual answer is 20.
Suppose all 20 numbers are of value =1 then,
1+1+1....till 20. Thier sum will be 20.
Avg=sum of all number/total number.
Avg= 20/20.
= 0.
So, as for question is concern there is no option with 20. The nearest 19 will do.
Suppose all 20 numbers are of value =1 then,
1+1+1....till 20. Thier sum will be 20.
Avg=sum of all number/total number.
Avg= 20/20.
= 0.
So, as for question is concern there is no option with 20. The nearest 19 will do.
Pooja said:
9 years ago
Your explanation is good @Tarun.
Nobi said:
9 years ago
@Amin Ullah.
Since when 20/20 = 0.
Since when 20/20 = 0.
Pingal rami said:
8 years ago
Your explanation is good, Thanks @Prabhat Kr.Singh.
Trishul said:
8 years ago
Very good explanation. Thank you all.
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