a four digit serial number
needs to be created using
digits 0-9. first digit is
even , no digit is repeated ,
last digit is odd
First digit is even: 4 choices (assuming zero is excluded)
Last digit is odd: 5 choices
Eight digits remain for the second digit, and 7 for the third (no repetition).
Total=product of all four numbers.
To create a four-digit serial number using digits 0-9 with certain conditions, you can follow these steps:
1. Determine the first digit: Since it needs to be even, you can choose from digits 0, 2, 4, 6, or 8.
2. Determine the second digit: It needs to be different from the first digit. You can choose from the remaining digits (0-9), excluding the first digit you selected.
3. Determine the third digit: Again, it needs to be different from the first and second digits. You can choose from the remaining digits (0-9), excluding the first and second digit you selected.
4. Determine the fourth digit: It needs to be an odd digit and different from the first three digits. You can choose from the remaining odd digits (1, 3, 5, 7, or 9).
Once you have selected one option for each step, you will have created a four-digit serial number that meets the given conditions.