## Precalculus: Concepts Through Functions, A Unit Circle Approach to Trigonometry (3rd Edition)

$80,000$ different 5-digit numbers numbers
There are 8 selections for first choice ( because 0 and 1 are excluded), and 10 selections each for the second, third, fourth and fifth choices. Using multiplication principle of counting, the number of 5-digit numbers that can be formed with the given restrictions is: $= 8\times10\times10\times10\times10 \\= 80,000$.