Would it be correct to answer одна or одне if the context would refer to a feminine or neuter noun?
Why is "як багато" wrong?
That's a literal translation, but we don't really say when asking about quantity. It's more commonly used in the meaning "as many":
"Як багато хто з вас уже знає" - i'm confused why you used "знає" instead of "знаєте", if you or someone wouldn't mind explaining. Thanks in advance :)