No - an alloy isn't a unit of measure at all, but rather a term for a mixture of multiple elements. So the question is essentially saying that "a mixture contains..." - which is a pretty common ratio/problem-solving quant problem structure so you'll want to get used to seeing that.
At this point it's probably worth pointing out that if a term like that serves to throw people off disproportionately, the GMAT's extensive research on each question will filter it out of circulation. At a recent conference, their research team mentioned that it had to remove a question that mentioned the term "skim milk", because it was trending to be disproportionately confusing in countries that don't have a term for or concept of skim milk. So don't let the here be centered on alloys - it's a ratio question and the official exam will be certain to be as clear as possible on those kinds of things.