How many number between 1000 and 9999 in which all the integers are even?

Oh, dude, you're talking about four-digit numbers where every digit is even, right? So, we've got 2, 4, 6, and 8 to play with. Each place can have any of those four options, so it's like 4 choices for each of the 4 digits. That's 4x4x4x4, which is 256 numbers between 1000 and 9999 where all the digits are even.