Wich one of the following sentanses are correct: a) who's key is this?
b)whose key is this?
&
a)Sandra is the woman with scarf.
b)Sandra is the woman without a scarf.

"Who's" is a contraction for "Who is". "Whose" is the posessive form of Who. So the answer to the first sentence is "B".

In the second sentence, there's an article missing between "with" and "scarf". If you meant "with out", you are saying something like she's "with an out scarf". If you meant "with out a", again, you are saying she's WITH "out a scarf" (no sense, right?) "Without" (single word) means "not having", and there's and article ("a"), which helps the prepositional phrase "without a scarf" make sense. So, that makes "B" correct for that sentence.

I hope that all makes sense and helps. ;-)

I agree that both b) answers are grammatically correct.

b and b.

Their are two correct sentences here Ahmed.

The first correct answer is B) "whose key is this?"

because other wise you are saying "who is key is this" who's is a grouped who is.
The supposed higher class English right after Shakespeare's time and Queen Elizabeth the first. Well after that they started to abbreviate words like these two and angered the lower class who thought them arrogant.

You would use Who's like this "Who's going to lunch?"

The second correct answer is B)Sandra is the woman without the scarf

If you do not put "a" ,denoting a single, before the item it appears as an unfortunate affliction or a disease. It would also be very impolite to tell someone if she did have something wrong with her. unless of course it was a health professional trying to help heal her. So yes there are two correct answers as there are two correct sentences.

B) and B) are both correct
Hope this helped in time.

B & B. I believe that "whose" is the possessive form of "who." The second one is easy.

"B" in both cases.

Now, do your own damn homework.

i would say A and B but im pretty stupid :P