Question

The output of a subtractor is given by (if A, B and X are the inputs).

(a) A AND B XOR X

(b) A XOR B XOR X

(c) A OR B NOR X

(d) A NOR B XOR X

The question was posed to me by my college director while I was bunking the class.

Question is taken from Half & Full Subtractor in portion Arithmetic Circuits of Digital Circuits

Answer 1

Correct answer is (b) A XOR B XOR X

The explanation: The difference output of a subtractor is given by (if A, B and X are the inputs) A XOR B XOR X.