Using the digits 1, 2, 3, and 4, four-digit even numbers are formed without repeating a digit. How many numbers are possible?
Show hints
- Only 2 and 4 can be in the last position.
- Multiply 2 choices for the last digit by 3 × 2 × 1 arrangements.
Show the answer and solution
Answer: 12
The last digit must be 2 or 4, giving 2 choices. The other three digits can be arranged in 3 × 2 × 1 ways. The total is 2 × 6 = 12 numbers.