How many prime implicants are in this Karnaugh map?

[kukumaluboy]

I need to find the total number of Prime Implicants in a Kmap

Is the one in red also a prime implicant?

 

[Korisnik]

Prime implicants are the biggest quadratic groups you can create from certain adjacent 1-cells. So, since you can form that quadratic group, and since it's the biggest possible (together with [4, 5, 7, 6]) -- yes.

 

[kukumaluboy]

Thanks!