It is given that a woman gives birth to a baby boy. Her second child is also a baby boy. Now she is about to give birth to her third child. We have to determine the probability of the child to be a girl.
Here, the probability of the child to be a girl would be 50 % or 1 out of 2.
There are two possibilities and the possibilities would result a boy child or a girl child. So there are two possible outcomes and is equally likely with each child birth.
Also each child birth is an independent event, so the probability that the one results will occur do not depend on the previous births.
Firstly, it cannot be bacteria because bacteria is prokaryotic with no membrane bound organelles. And it's cell wall is made of murein (peptidoglycan).
It certainly isn't a virus virus because a virus has no true cellular structure.
Let's see why we ruled out the other 3 eukaryotic kingdoms:
It can't be an animal because animal cells don't have cell walls and are multicellular.
It can't be fungi because its cell wall is made of chitin, not cellulose.
It can't be a plant because plants are all multicellular.