Question

1. how many possible codes can be formed with a lock that uses 5 numbers from 0-9? 10,000 100 100,000 1000

Explanation:

Step1: Identify each digit's options

Each of the 5 digits in the code can be any number from 0 - 9, so there are 10 choices for each digit.

Step2: Apply the multiplication principle

For a 5 - digit code, the total number of possible codes is calculated by multiplying the number of choices for each digit. That is $10\times10\times10\times10\times10$.
Using the formula for exponents, $10^5=\ 100000$.

Answer:

100,000 (corresponding to the option "100,000")