#### Answer

$\frac{1}{1,000,000,000}$.

#### Work Step by Step

There are 10 digits, so by using the fundamental counting rule we can get the number of possibilities: $10\times10\times10\times10\times10\times10\times10\times10\times10=1000000000$. We also know that $probability=\frac{number \ of \ good \ outcomes}{number\ of\ all\ outcomes}$, therefore $P=\frac{1}{1,000,000,000}$.