The average of first 80 non-zero positive numbers is:
Select
A) 22.25  B) 31.25  C) 35  D) 40.5  E) None of these
Explanation :   Sum of first n natural numbers = n (n + 1)/2   So, average of first n natural numbers =   n (n + 1)/2n = (n + 1)/2   Required average = (80 + 1)/2 = 81/2 = 40.5.   Answer : 40.5
<result>D</result>
The average of first 80 non-zero positive numbers is: