If A, B and C are the inputs of a full adder then the carry is given by
A)a and b or (a or b) and c
B)a or b or (a and b) c
C)(a and b) or (a and b)c
D)a xor b xor (a xor b) and c

Question

If A, B and C are the inputs of a full adder then the carry is given by                      
A)a and b or (a or b) and c
B)a or b or (a and b) c
C)(a and b) or (a and b)c
D)a xor b xor (a xor b) and c

Quizplus · Accepted Answer

The carry output of a full adder is given by (A AND B) OR ((A XOR B) AND C). This is because the carry is generated either when both A and B are 1 (A AND B), or when one of A or B is 1 (A XOR B) and C is also 1, which requires an AND operation with C. Option A, "a and b or (a or b) and c", closely represents this logic, albeit with a slight misrepresentation in the use of OR instead of XOR for (a or b). However, given the options, A is the closest to the correct logic for carry in a full adder.

If A, B and C Are the Inputs of a Full