Question 1173645
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The only restriction on the number to be formed, other than the requirement that the digits be all different, is that the number must be even.<br>
That means the units digit must be even; the other digits can be any digits.<br>
Since the only restriction is on the units digit, choose it first.  Among the given digits, 4 of them are even, so there are 4 choices for the units digit.<br>
After that, there are 8 digits left to choose from; and you can choose the tens, hundreds, and thousands digits in any order you want.<br>
Because of the requirement that the digits all be different, there are 8 choices for the next digit you choose, 7 choices for the one after that, and 6 choices for the last.<br>
So the total number of 4-digit even numbers that can be formed from the given digits is 4*8*7*6 = 1344<br>