A good answer might be:

1100 1100 (correct)

More Practice Subtraction

The number to be subtracted is negated by the usual means (reflect the bits, add one):

0101 1100   1010 0111

Then the "binary addition algorithm" is used:

00100 111         
 0010 0101   =  3710
 1010 0111   = -8910
 ---------    -----
 1100 1100     -5210

Since the carry into the most significant column is the same as the carry out of that column the result is correct. The answer came out negative, but that is fine.

You must practice the "binary addition algorithm" until you are sick of it. Or you can change your major to Art History (and leave the high paying jobs to the rest of us). Here is another problem:

QUESTION 27:

Subtract 0101 1001 from 1110 0101.     Is the result correct or not?