Question

# The total number of numbers of not more than 20 digits that are formed by using the digits 0,1,2,3 and 4 is${\text{A}}{\text{. }}{{\text{5}}^{20}} \\ {\text{B}}{\text{. }}{{\text{5}}^{20}} - 1 \\ {\text{C}}{\text{. }}{{\text{5}}^{20}} + 1 \\ {\text{D}}{\text{. None of these}} \\$

$5 \times 5 \times 5 \times ...20{\text{ times}}$. So , the total number of numbers possible is ${5^{20}}$.