Aptitude - Average - Discussion

Hey Jeevanandham ans will never 20,.

Because if all 20 numbers are positive then their avg will never be zero,.

And Vamsikrishna according to question they ask about numbers greater than zero.

So you cant put zero,.

Because zero equals to zero, not greater than zero.

in this question,
how many numbers may be graterthan zero.
if any number is graterthan 1.the avg is not zero.so, no number graterthan zero.
ans:A

Here in this question they asked about the almost that means max numbers of numbers those are greater than 0.

>>> So 19 is the answer because we are not considering the 0 because he asked >0.

>>> If he ask about min number of numbers we can say 1.

Thanks @Harika.

Listen, guys.

Question is at most numbers are greater than zero. At most mean maximum.

So let's do.

Av of 20 no are zero.
Lets count.

0+1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19/20=0. Ok.

Count how many no are greater than zero? 19 then answer is 19.

First when average can be Zero:
0(Sum of observation)/20 Number of Observations =0 is answer (Average).

Than means we must get 0 sum on the top of /20 that will make average Zero.

Even single nagative number can make 0 on top of /20. If sum of 19 numbers is +1 one nagative number -1 can make it zero you can assume sum of 19 numbers as positive and put same nagative number to make it Zero.


Now coming to answer, they are asking how many number can be above 0 i.e. in positive (numbers below zero are nagative). 19 Max number can be positive to make one nagative number 0 so that we get average zero.

Hope it's clear now.

It may be possible that all numbers are negative and only one is positive like
(-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1-1+19)/20 = 0.

0 = (numbers sum)/20.
0*20 = (numbers sum).
0 = (numbers sum).

Note :-
None of the numbers was Greater than 0.
So, the answer is "0"

I don't unterstand this answer. Please any one explain.

Please try this:

Sum of 10 +ve no's + 10 -ve no's = 0

So, sum is zero.

The answer may be 20.