The average of 20 numbers is zero. Of them, at the most, how many may be greater than zero? Choose the most appropriate option.
A) 16
B) 17
C) 18
D) 19
E) 20
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).   Answer 19
<result>D</result>
The average of 20 numbers is zero. Of them, at the most, how many may be greater than zero?