f(a,b,c) = Summation(0,2,3,7)

 g(a,b,c) = Summation(1,4,6,7)

 Truth Table

 a  b  c  |    f       g

 0  0  0  |    1       0

 0  0  1  |    0       1

 0  1  0  |    1       0

 0  1  1  |    1       0

 1  0  0  |    0       1

 1  0  1  |    0       0

 1  1  0  |    0       1

 1  1  1  |    1       1

 The function f = a'b'c' + a'bc' + a'bc + abc.

 The function g = a'b'c + ab'c' + abc' + abc.