How many even four-digit numbers can be made from the digits 1, 2, 3, 4, using each exactly once?
Show hints
- For an even number, choose the last digit.
- After it, rearrange the three remaining digits.
Show the answer and solution
Answer: 12
Last digit 2 or 4, two choices. The remaining three digits can be rearranged 3 × 2 × 1 in the following ways: 12.