Question: a let fx1 x2 xn be equal to...

(a) Let f(x1, x2, ... , xn) be equal to 1 if and only if exactly k of the variables equal 1. How many prime implicants does this function have?

(b) Repeat (a) for the case where f assumes the value 1 if and only if k or more of the variables are equal to 1.

(Note: The above functions are known as symmetric.)