Question

How many three digit natural numbers are divisible by $3$?

Answer 1

The three digit natural numbers start from $100$ and ends with $999$.

The first three digit number which is divisible by $3$ is $102$.

The last three digit number which is divisible by $3$ is $999$.

The number of three digit numbers divisible by $3$ are $\frac{999}{3}-\frac{102}{3}+1=333-34+1=300$.