If your teacher is referring to four digit numbers with those tiles, where the tiles cant repeat, then we have 2 choices for the last slot (the units digit). Those two choices are: 6,8.
Recall that a number is only even if and only if the units digit is even (0,2,4,6,8).
Once a choice has been made for the units digit, we have...
- 3 choices for the thousands digit (whatever we didn't pick for the units digit)
- 2 choices for the hundreds digit
- 1 choice for the tens digit
Overall, we have 2*3*2*1 = 12 different four digit numbers possible.
Those 12 numbers are:
- value = 1658
- value = 1568
- value = 5168
- value = 5618
- value = 6158
- value = 6518
- value = 1856
- value = 1586
- value = 5186
- value = 5816
- value = 8156
- value = 8516
