Relationship between A, B, and C.

[ninjaluc79]

There were once three people I will name A, B, and C for simplicity purposes.

If A and B are born of the same father, but not of the same mother;
and B and C are born of the same mother, but not of the same father;
how are A and C related to each other?

F1 + M1 = A
M1 + F2 = B
F2 + M2 = C

[Xelinis]

Dark Helmet: I am your father's brother's nephew's cousin's former roommate.
Lone Starr: What's that make us?
Dark Helmet: Absolutely nothing!

[End obligatory Spaceballs reference]

So yea, unless you can supply marital details, I don't think that makes A and C anything.

[ninjaluc79]

Well, that's what I was thinking. Except that A is B's half-bro, while B is C's half-bro, but A and C aren't related anyway.

I'll add some more info, although that may not change anything:

M1 and M2 are sisters.
M1 is married to F2.

Aha! They're cousins! Okay, what else?

[Nikisaur]

Ahaha. I was looking at that as Male1 and Male2, and Female1. I got confused when you said they were sisters!

It makes A and C cousins. Because the closest ancestor they share is their maternal grandparents. Bringing the marriage into it makes them step-brothers aswell? It also has the potential to make them very confused.