Answer:
(a) 1/2
(b) Possible Genotype =

Possible phenotype = non-haemophilic
Step-by-step explanation:
Let the allele for haemophilia be h, the alternate form would be H.
Genotype of non-haemophilic man would be

Genotype of non haemophilic woman could be either

If they have an haemophilic son, it means the genotype of the woman is

Crossing the two:
x
=

(a) One out of the two sons is affected. Hence the probability of their next son having haemophilia is 1/2.
(b) the possible genotypes for their daughters are
and both of them have no haemophilia.