British sterling silver is a copper-silver alloy that is 7.5% copper by weight. How many grams of pure copper and how many grams of British sterling silver should be used to prepare 200 grams of a copper-silver alloy that is 10% copper by weight? (round to the nearest tenth)

Answer 1

amount of silver --- x g
amount of copper --- 200-x g

.075x + 200-x = .1(200)
-.925x = -180
x = appr 194.6 g