Answer: The chance of he being her father is 0.
Explanation:
The mother with blood type B,
The father with blood type AB,
Mrs Wade the offspring with blood type O.
Possible genotypes for both parents:
Mother is BB or BO,
Father is AB.
Since the offspring is having blood type O, we consider a cross between BO of mother and AB of father.
Mother father
Parents gametes: BO x. AB
Offsprings. AB, AB, AO, BO.
From the cross the genotypes that are possible of carrying O are AO and BO but this cannot be used to say that the baby will have blood type O because the O present in AO and BO is recessive gene.
Also, for the baby to have blood type O, she must have gotten one allele from each parent to have a genotype OO which is not so in this case.
Therefore, the chance that he is her father is 0.