The average of 20 numbers is zero. Of them, at the most, how many may be greater than zero?  Choose the correct choice from the following answers.
A) 0
B) 1
C) 10
D) 19
E) 8
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).   Answer : 19
<result>D</result>
The average of 20 numbers is zero. Of them, at the most, how many may be greater than zero?