10 Digit Number

Algebra Level 2

How many $10$ -digit numbers can be formed using only the digits $2$ and $5$ ?

10!

\dfrac{10!}{2}

2^{10}

1 solution

Oliver Papillo
Dec 26, 2017

In generating one of these numbers, we would have $2$ options for each digit, yielding a total of $2^{10}$ numbers.