SOLUTION: 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 prepar
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Question 1107512: 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 320 grams of a copper-silver alloy that is 18% copper by weight? (Round your answers to one decimal place.)
copper amt + British silver amt = total copper amt
x + 0.075*(320-x) = 0.18*320
We take x grams of pure copper and (320-x) grams of British sterling silver
to get 320 grams of 18% copper.
x + 0.075*320 - 0.075x = 0.18*320
0.925x = 0.18*320 - 0.075*320 = 33.6 ====> x = = 36.324.
Answer. 36.324 grams of pure copper.
Check. = 0.18. ! Correct !
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