An alloy of brass is composed of 84.6% copper, 5.20% tin, 6.70% lead, and zinc. The number of pounds of zinc required to make 520.0 pounds of alloy is "_____"
Obviously this is a homework question for my trade school. What I don't get about this is the wording. The zinc equals 3.5% of an alloy from what I put together. I don't understand though. Do these percentages amount to the percentages of a pound of the named material? The way it's worded doesn't seem to make sense to me. If I did this the way my brain is trying to put it together, the answer would be 148.5714285714286. Can somebody fact check this for me?