Finding how many integers divisible by n between a-b? If I have a set of integers: $[a,b]$, how can I find the number of integers in the set are divisible by $n$? Is it possible to use a combination? Also, is there any way to display this graphically?

The number of positive integers $\le b$ those divisible by $n$ is $$\left\lfloor\frac bn\right\rfloor$$
The number of positive integers $<a$ those divisible by $n$ is $$\left\lfloor\frac{a-1}n\right\rfloor$$
