Question

The mean 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 1

It is given that mean of 20 numbers is zero.

i.e. average of 20 numbers is zero.

i.e. sum of 20 numbers is zero.

Thus, at most, there can be 19 positive numbers.
(such that if sum of 19 positive numbers is x, 20th number will be −x)

Hence, the correct answer is option (d).