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 337071: 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?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
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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?
:
Let x = amt of pure copper required
then
(200-x) = amt of 7.5% copper alloy required
:
Write a percent copper equation in decimal form
x + .075(200-x) = .10(200)
x + 15 - .075x = 20
x - .075x = 20 - 15
.925x = 5
x = 5%2F.925
x = 5.4 grams of pure copper required
then
200 - 5.4 = 194.6 grams of 7.5% alloy required
:
:
Check solution
5.4 + .075(194.6) = .10(200)
5.4 + 14.595 = 20
19.995 ~ 20