A man whose father was blood type 1 and his mother had blood type 3 has a third blood type.

A man whose father was blood type 1 and his mother had blood type 3 has a third blood type. He marries a woman with a fourth blood group. What is the likelihood that this marriage will give birth to a child with a third blood group?

The genotype of a man is IBi (blood group 3), as his mother had a 3 blood group, and his father had 1 blood type
Female genotype IAIB (blood group 4).
crossing scheme:
P: IAIB x IBi
G: IA, IB IB, i
F1: IAIB, IAi, IBIB, IBi
4 gr. Cr., 2 gr. Cr., 3 gr. Cr., 3 gr. Cr.
The probability of having a child with a 3 blood group is 50%.