The average of 20 numbers is zero. Of them, at the most, how many may be greater than zero? Select:
A) 19  B) 20  C) 22  D) 45  E) 52
A   19   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).
<result>A</result>
The average of 20 numbers is zero. Of them, at the most, how many may be greater than zero?