A bunch of related letters

Patrick is answering a series of questions where he is given a word and he has to write a single character. He knows how to answer these and quickly answers-

• fsmss $\to$ s
• wsffs $\to$ 0
• fwmhdhdbfw $\to$ m
• bsmhb $\to$ 0 or b
• dbmhsm $\to$ w

While answering, he took a break. However, when he returned from the break, he forgot the process he found the answers, help him figure out the following-

• fdhdbmhwmh $\to \ ?$
• bmhsmhwfwdh $\to \ ?$
• smhdfwsfdbmh $\to \ ?$

Note

bsmhb $\to$ 0 or b means both 0 and b are valid answers. In case of multiple answers any valid one is accepted.

Hint

Don't sweat over the wordplay tag, it really isn't necessary to solve the puzzle.

• A single letter, or a single character? Is the '0' meant to be an 'o'? – LogicianWithAHat Aug 25 '15 at 10:35
• he is given a word and he has to write a single letter -> Is the "0" meaning null ? – The random guy Aug 25 '15 at 10:47
• @LogicianWithAHat A single character, corrected. – Rohcana Aug 25 '15 at 10:57
• At first I thought this was going to be 'figure out what sequence was shortened to first letter', but then I couldn't match any.. (mtwtfs would be 's' - days of the week). Maybe it's just not first letters? – Tim Couwelier Aug 25 '15 at 14:02
• Notice that only the letters "B, D, F, H, M, S, and W" are ever used either in the sequences or the answers. I think this is a big part of it. – dramzy Aug 25 '15 at 15:38

The letters in the sequences are all from the (alphabetically ordered) set b d f h m s w.

If we pair these up differently we get:

h/w: husband / wife
f/m: father / mother
b/s: brother / sister
d/s: daughter / son
- note that "s" seems to stand for both sister and son.

The sequences he has already identified are:

fsmss -> s : my father's son's mother's son's sister is my sister
wsffs -> 0 : my wife's son's father's father's son is me (represented by NULL)
fwmhdhdbfw -> m : my father's wife's mother's husband's daughter's husband's daughter's brother's father's wife is (drumroll please) my mother
bsmhb -> 0 or b : my brother's son's mother's husband's brother is either me or my brother
dbmhsm -> w : my daughter's brother's mother's husband's son's mother is my wife

So the new questions are:

fdhdbmhwmh -> f : my father's daughter's husband's daughter's brother's mother's husband's wife's mother's husband is my father
bmhsmhwfwdh -> f : my brother's mother's husband's son's [note: sister doesn't work here or I end up with my grandfather] mother's husband's wife's father's wife's daughter's husband is my father
smhdfwsfdbmh -> 0 : my son's mother's husband's daughter's father's wife's son's father's daughter's brother's mother's husband is me.

• Actually, you don't need sister at all. You can replace sister by son, and the answers still remain valid, anyways good work, By the way, did you have a look at the title? – Rohcana Aug 25 '15 at 23:37
• Huh, just noticed that, nice. – dramzy Aug 26 '15 at 13:38

The more I thought about this, the more I realized that it isn't right. Maybe it will help someone else though.

Given that:

• 'w' can never follow an 's'.

• 'm' and 'w' are considered matching (they're just upside down!).

• '0' means there is no such letter, or adding no letters is sufficient.

Then:

What letter from the set "b d f h m s w" when added to the front makes the front and back letters match?

fsmss → s

fsmss → s (sfsmss)

wsffs → 0

wsffs → 0 (since a w can not follow an s there is no letter)

fwmhdhdbfw → m

fwmhdhdbfw → m (mfwmhdhdbfw)

bsmhb → 0 or b

bsmhb → 0 or b (Adding no letters is fine here, but if you add a b you still match.

dbmhsm → w

dbmhsm → w (wdbmhsm)