Let us take an example with radix 10, using 2 digits we can write from 0,1,23....95,96,97,98 and 99 that is total 100= [tex]10^{2} [/tex] numbers
Similarly using 3 digits, we can write from 0 to 999= 1000 = [tex]10^{3}[/tex] numbers.
Generalizing this we can express [tex]r^{k}[/tex] numbers using k-digits in a radix r.
