Digital Arithmetic Operations and Circuits - Technical MCQs

Q1:

Convert each of the decimal numbers to two's-complement form and perform the addition in binary.
+13 –10
add –7 add +15

A 0001  0100    0000  0101

B 0000  0110    0001  1001

C 0000  0110    0000  0101

D 1111  0110    1111  0101

ANS:C - 0000  0110    0000  0101

+13 = 1101.
-7 = 0111(2's complement=1001).

Add both of 2 numbers=>1101+1001 = 0110,
Then, 0000 0110.

Similarly,
-10 = 1010(2's complement=0110)
+15 = 1111.

Add both of 2 numbers=>0110+1111=0101.
Then, 0000 0101.