Question

Find the average of first 61 natural number ?
1. 31
2. 30
3. 28
4. 25

Answer 1

Correct Answer - Option 1 : 31

Given:

First 61 natural numbers are = 1, 2, 3, 4,.....,61

Formula used:

Average of first 'n' natural numbers = (n + 1)/2

Calculation:

Here, n = 61

According to the question

Average of first 'n' natural numbers = (61 + 1)/2

⇒ 62/2 = 31

∴ The average of first 61 natural number is 31.

 

Average of squares of first 'n' natural numbers = [(n + 1)(2n + 1)]/6

Average of cubes of first 'n' natural numbers = [n(n + 1)²]/4