In all, there are 9000 4-digit numbers from 1000 to 9999. Of them, exactly one fourth of the 9000 numbers are divisible by 4. Thus 9000/4 = 2250 numbers of 9000 are divisible by 4. The rest, i.e. 9000 - 2250 = 6750 4-digit numbers are not divisible by 4.