Problema Solution

21. For thousands of years, gold has been considered one of

Earth’s most precious metals. One hundred percent pure

gold is 24-karat gold, which is too soft to be made into

jewelry. In the United States, most gold jewelry is 14-karat

gold, approximately 58% gold. If 18-karat gold is 75%

gold and 12-karat gold is 50% gold, how much of each

should be used to make a 14-karat gold bracelet weighing

300 grams?

Answer provided by our tutors

Let

x = grams of the 18-karat gold

y = grams of the 12-karat gold

x + y = 300

0.75x + 0.50y = 0.58*300

........

click here to see the system of equations solved for x and y

........

x = 96 grams

y = 204 grams

96 grams of 18-karat gold and 204 grams of 12-karat gold should be used to make the bracelet.