Question

How many NOT gates are required to implement the Boolean expression: X = AB’C + A’BC?

(a) 2

(b) 3

(c) 4

(d) 5

I had been asked this question by my school principal while I was bunking the class.

I need to ask this question from Fast Adder & Serial Adder topic in portion Arithmetic Circuits of Digital Circuits

Answer 1

The correct answer is (a) 2

The best I can explain: Since in the given expression two inputs are complemented. So, we require two NOT gate at the input. A NOT gate is a basic gate which accepts a single input and produces a single output, which is the inverted version of the input.