Joe has a ring weighing 16 grams made of an alloy of 20% silver and the rest gold. He decides to melt down the rings and add enough silver to reduce the gold content to 69% . How many grams of silver should he add?
Physics(class) /Math (problem) - Steve, Thursday, October 4, 2012 at 10:29am
considering just the mass of the silver,
(.20)(16)+x = (.31)(16+x)
so, add 2.55g of silver