A Woman Of Blood Type B Marries A Man Of Blood Type A. Their First Child Is Blood Type O. What Is The Probability That Their Second Child Will Have A Blood Type Other Than O?

[Almila97]

A woman of blood type B marries a man of blood type A. Their first child is blood type O. What is the probability that their second child will have a blood type other than O?

[Mamyalynne]

If you have a range of questions better to put the, all in one thread and number them.

[Jonathan-Joe]

The woman is of blood type B so must have a "B" type gene
the man is of blood type A so must have a "A" type gene
the first child is of blood type O so each parent must have an "O" type gene.
So woman is gene type "BO", man is gene type "AO"
The second child could have
"B" + "A" giving AB blood type
"B" + "O" giving B blood type
"O" + "A" giving A blood type
or "O" + "O" giving O blood type
These cases are equally likely so probability that second child is of blood type = 1/4 (0.25)

[Baldric]

https://biology.stackexchange.com/questions/59634/a-stem-cell-usually-becomes-determined-before-differentiation-true-or-false

^^ the source of many questions it would appear ;o)

[Jonathan-Joe]

My answer should have finished " ... probability that second child is of O blood type = 1/4 (0.25). Also I took your question the wrong way round.
To answer your question as stated - the Probability That Their Second Child Will Have A Blood Type Other Than O is 1 - 0.25 = 0.75.