A=Mother, B = Father, P(A\\cup B) = 17\\%P(A∪B)=17%, P(B) = 12\\%P(B)=12%, P(A\\cap B) = 6\\%P(A∩B)=6%. Since we know P(A\\cup B) = P(A) + P(B) - P(A\\cap B)P(A∪B)=P(A)+P(B)−P(A∩B) we get
17\\% = P(A) + 12\\% - 6\\%17%=P(A)+12%−6%.