Question

Find the average of first 40 natural numbers

Answer 1

sum  of first n natural numbers=n(n+1)/2
So,sum of 40 natural numbers=(40*41)/2=820
Therefore  the required average=820/40=20.5
hence the answer is 20.5

Answer 2

Given:

First 40 natural number

To Find:

The average of the first 40 natural numbers

Solution:

Sum of n natural number is calculated as n(n+1)/2

Average of n natural numbers will be

= sum of n natural numbers/n            

=(n(n+1)/2)/n

=(n+1)/2

So, we have to find the average of 40 natural numbers.

We will put n = 40

(n+1)/2 = (40+1)/2

          =41/2

          = 20.5

Hence, the average of the first 40 natural numbers is 20.5