Question

The 2’s complement of 10.11 :

(a) 10

(b) 0.010

(c) 01.01

(d) 10.01

This question was posed to me during an internship interview.

Origin of the question is The Hexadecimal Number System in chapter Number Systems of Computer Fundamentals

Answer 1

Correct answer is (a) 10

Easiest explanation: The 1’s complement of a number is obtained by reversing the bits with value 1 to 0 and the bits with value 0 to 1.  Here, 10.11 gets converted to 01.00 in its 1’s complement format. Further, to convert 1’s complement into 2’s, we add 1 to the result.  Here, 01.00+1=10.00.