/sci/entists, I'm going to ask you a very fucking stupid question that doesn't really make any sense, but I don't know how else do explain.

I'm doing some molarity questions

What volume in Liters of a 4.50 M HCl(aq) solution contains 6.90 g of HCl (Mm = 36.46 g/mol)? Report your answer to three decimal places.

So, moles first, 6.90/36.46, we have 0.18924 moles in ? litres to get a 4.50 molarity solution

So I figured ok, 4.50 = 0.18924/x, in other words, 0.18924/4.50 = the molarity

i was kind of just guessing on a whim, and it turned out to be right
but i don't /understand/ why it was right, i know molarity = moles/litres of solution

my stupid ass question is this: how did x /know/ to default to litres? like how does it count as litres? obviously x doesn't /know/ but why would the result be right for litres, but say, not if it was asking for millilitres? there's something plain as day i'm missing. it's like, the math doesn't know whether the fuck x=y/z means ass=tits/bread or this ratio = this thing/that thing, so why did it just happen to give me the correct number of litres?

I'm mildly retarded, I think, never diagnosed but I'm just really slow and dumb, but I want to be a research scientist someday.

So what gives?

inb4 give up science/math
i'll give up when im dead m8