Question

An alloy contains 39.5 mass% silver (Ag) and has density og 7.86 g/ml What volume of alloy would be needed to contain 12.0g of pure Ag?

Answer 1

g alloy x 0.395 = 12g
g alloy = 12/0.395 = about 30g but you need to be more exact than that.
Then volume = mass/density