Joe has a ring weighing 20 grams made of an alloy of 19 % silver and the rest gold. He decides to melt down the rings and add enough silver to reduce…

Joe has a ring weighing 20 grams made of an alloy of 19 % silver and the rest gold. He decides to melt down the rings and add enough silver to reduce the gold content to 73 %. How many grams of silver should he add?