A circuit outputs a digit in the form of 4 bits. 0 is represented by 0000, 1 is represented by 0001, …, 9 by 1001. A combinational circuit is to be designed which takes these 4 bits as input and output as 1, if the digit is ≥ 5, and 0 otherwise. It only AND, OR and NOT gates may be used, what is the minimum number of gates required?

A circuit outputs a digit in the form of 4 bits. 0 is represented by 0

1.	A circuit outputs a digit in the form of 4 bits. 0 is represented by 0000, 1 is represented by 0001, …, 9 by 1001. A combinational circuit is to be designed which takes these 4 bits as input and output as 1, if the digit is ≥ 5, and 0 otherwise. It only AND, OR and NOT gates may be used, what is the minimum number of gates required?
A.	4
B.	3
C.	2
D.	1
Answer» C. 2