To determine how many 5-digit numbers can be formed using the digits 0-9, we need to consider the rules for forming a 5-digit number:
- The first digit cannot be 0, as that would make it a 4-digit number.
- Each of the remaining four digits can be any digit from 0 to 9.
Let’s break it down:
- First Digit: Since it cannot be 0, there are 9 possible choices (1-9).
- Second Digit: Any digit from 0 to 9 is allowed, so there are 10 possible choices.
- Third Digit: Again, any digit from 0 to 9 is allowed, so there are 10 possible choices.
- Fourth Digit: Any digit from 0 to 9 is allowed, so there are 10 possible choices.
- Fifth Digit: Any digit from 0 to 9 is allowed, so there are 10 possible choices.
To find the total number of 5-digit numbers, we multiply the number of choices for each digit:
Total 5-Digit Numbers = 9 × 10 × 10 × 10 × 10 = 90,000
Therefore, there are 90,000 possible 5-digit numbers that can be formed using the digits 0-9.