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

• A. $5^{20}$
• B. $5^{20}-1$
• C. $5^{20}+1$
• D. None of these

Answer 1

The correct option is A $5^{20}$

Each of the place out of 20 ($\because$ We can have maximum 20 digit number) has 5 possibilities. So, Total number of numbers

formed by $0,1,2,3,4$ are

$=5\times 5\times \cdots \times 5\left(20times\right)=5^{20}$