47. The average of 20 numbers is zero. Of them, at the most, how many may be greater than zero?
A. 0 B. 1 C. 10 D. 19
Answer: D.
Explanation:
Average of 20 numbers = 0.
Therefore sum of 20 numbers = (0 × 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).
