Question

In 16-bit 2’s complement representation, the decimal number -28 is:
1. 1111 1111 0001 1100
2. 0000 0000 1110 0100
3. 1111 1111 1110 0100
4. 1000 0000 1110 0100

Answer 1

Correct Answer - Option 3 : 1111 1111 1110 0100

2	28
2	14	0
2	7	0
2	3	1
2	1	1
	0	1

 

28₁₀ = (11100)₂ = (0000 0000 0001 1100)₂

-28₁₀ = 2’s complement of 0000 0000 0001 1100

2’s complement of 0000 0000 0001 1100 = 1111 1111 1110 0100

Note:

Tricks to find: 2’s complement

Start reading the bits from LSB (right hand side) and write it unless first 1 is encounter, leave the first 1 as it is and complement the remaining bits.