Question

Given that numbers A and B are two 8-bit 2’s Complement numbers with \( A = 11111111 \), \( B = 11111111 \). Then sum \( A + B \) is:

• A. 00000010
• B. 11111100
• C. 11111110
• D. 00000000

Hint:

In 2’s complement, overflow is ignored. The result still correctly represents the value in modulo 256 arithmetic.

Answer 1

The Correct Option is C

Step 1: Interpret A and B in 2’s complement \[ A = 11111111 \Rightarrow -1,\quad B = 11111111 \Rightarrow -1 \] Step 2: Add them: \[ -1 + (-1) = -2 \] Step 3: Represent -2 in 8-bit 2’s complement: \[ +2 = 00000010 \Rightarrow -2 = 11111110 \]