The arithmetic mean (average) of the first 10 whole number is

Answer: Option D

According to the question,
First 10 whole numbers are = 0, 1, 2, 3, 4, 5, 6, 7, 8, 9
∴ Average of 10 whole numbers
$$\begin{array}{rl}& =\frac{0+1+2+3+4+5+6+7+8+9}{10}\\ & =\frac{45}{10}\\ & =4.5\end{array}$$