![What is the minimum number of 2-input NOR gates required to implement a 4-variable function expressed](https://www.gkseries.com/blog/wp-content/uploads/2023/08/What-is-the-minimum-number-of-2-input-NOR-gates-required-to-implement-a-4-variable-function-expressed.jpg)
Q. What is the minimum number of 2-input NOR gates required to implement a 4-variable function expressed in sum-of-minterms form as f = Σ (0, 2, 5, 7, 8, 10, 13, 15)? Assume that all the inputs and their complements are available. Answer: .
Ans:
K-map for given,
f = Σ(0, 2, 5, 7, 8, 10, 13, 15)
![](https://www.gkseries.com/blog/wp-content/uploads/2023/08/Screenshot-494.png)
Therefore,
f = BD +B’D’
= (B’ + D).(B + D’)
Since all the inputs and their complements are available, so circuit implementation using NOR gate:
![](https://www.gkseries.com/blog/wp-content/uploads/2023/08/Screenshot-495.png)
F can be implemented using 3 NOR gates.
So, option (A) is correct.