To find the average of the first 20 whole numbers, follow these steps:

Step 1: Identify the first 20 whole numbers

Whole numbers start from 0. So, the first 20 whole numbers are:
0, 1, 2, 3, ..., 18, 19

Step 2: Calculate the sum of these numbers

The sum of the first nnn whole numbers (from 0 to n−1n-1n−1) is given by the formula:

Sum=n×(n−1)2\text{Sum}=\frac{n\times (n-1)}{2}Sum=2n×(n−1)​

For n=20n=20n=20:

Sum=20×192=3802=190\text{Sum}=\frac{20\times 19}{2}=\frac{380}{2}=190Sum=220×19​=2380​=190

Step 3: Calculate the average

Average is the sum divided by the number of terms:

Average=19020=9.5\text{Average}=\frac{190}{20}=9.5Average=20190​=9.5

Final answer:

The average of the first 20 whole numbers is 9.5.