The purity of gold is measured in karats, with pure gold being 24 karats. Other purities of gold are expressed as proportional parts of pure gold. Thus 18-karat gold is StartFraction 18 Over 24 EndFraction 18 24, or 75% pure gold; 12-karat gold is StartFraction 12 Over 24 EndFraction 12 24, or 50% pure gold; and so on. How much 1212-karat gold should be mixed with pure gold to obtain 3030 grams of 2222-karat gold?