Question

Which of the following is false?

(a) x+y=y+x

(b) x.y=y.x

(c) x.x’=1

(d) x+x’=1

I had been asked this question during an online interview.

I need to ask this question from Fundamental Concepts & Postulates topic in chapter Boolean Algebra and Logic Circuits of Computer Fundamentals

Answer 1

Right answer is (c) x.x’=1

The explanation is: The first and second option describes the commutative law. The fourth option holds true since if x=1, then x’=0, and x+x’=1. Third option is incorrect because on multiplication of a boolean value with its complement the result will always be 0.