1 11 1 1
0F4A → 0000 1111 0100 1010
420B → 0100 0010 0000 1011
0101 0001 0101 0101 → 0x5155
In the answer (above), the carry out of zero from the left column indicates that overflow did not happen.
Sometimes a hex addition problem is easy enough to do without converting to binary:
014A 4203 434D
It may be helpful to use your digits (fingers) in doing this:
to add A+3 extend three fingers and count "A... B... C... D".
Compute the following sum using 8 bits. Is there overflow?
1101 0010
0110 1101