Question

Two 4-bit 2's complement numbers 1011 and 0110 are added. The result expressed in 4-bit 2's complement notation is

• A. Cannot be expressed in 4-bit 2's complement
• B. 1101
• C. 0001
• D. 0010

Answer 1

The correct option is C 0001

$1011\leftarrow 2^{\prime }s\text{complement representation of}+5$
$0110\leftarrow 2^{\prime }s\text{complement representation of}10$
Addition of these two numbers will give 15 i.e. $(1111{)}_2$
15 in 2's complement form $=(0001{)}_2$