$($a$)$ In order to understand digital system, one must know basic binary arithmetic

since it is essential in all digital computers and in many other types of digital

systems. Such arithmetic is addition, subtraction, multiplication, division, $1\text{'}$s

complement and $2\text{'}$s complement.

i$.$ Explain the concept and $/$ or purpose of $1\text{'}$s complement and $2\text{'}$s

complement of binary numbers.

ii$.$ Using binary number system, please compute:

a$.,{43}_{16}+4E_{16}$

b$.,{20}_{16}+C{D}_{16}$