SOLUTION: An alloy of copper and tin is 20% copper. How many pounds of copper must be added to 20 pounds of the alloy to get an alloy that is 50% copper?

Question 248990: An alloy of copper and tin is 20% copper. How many pounds of copper must be added to 20 pounds of the alloy to get an alloy that is 50% copper?
Answer by ankor@dixie-net.com(22740) (Show Source): You can put this solution on YOUR website!
An alloy of copper and tin is 20% copper.
How many pounds of copper must be added to 20 pounds of the alloy to get an alloy that is 50% copper?
:
let x = amt of pure copper required
.20(20) + x = .50(x+20)
4 + x = .5x + 10
x - .5x = 10 - 4
.5x = 6
x = 12 lb of pure copper to accomplish this
;
;
Check:
.2(20) + 12 = .5(12+20))
4 + 12 = 16
RELATED QUESTIONS
An alloy of copper and tin is 20 percent copper. How many pounds of copper must be added... (answered by solver91311)

Forty pounds of an alloy of copper and tin contain 8 pounds of copper. How many pounds of (answered by rwm)

How many pounds of an alloy containing 60% copper must be melted with an alloy containing (answered by checkley77)

an alloy of tin and copper contains 14 pounds of tin and 26 pounds of copper. a second... (answered by ankor@dixie-net.com)

Babbitt metal is an alloy made up of 90% tin, 7% antimony, 3% copper. How many pounds of... (answered by solver91311)

How much of an alloy with 30% copper must be added to 25 pounds of a second alloy which... (answered by nyc_function)

How much of an alloy with 30% copper must be added to 25 pounds of a second alloy which... (answered by josgarithmetic)

An alloy of copper is 10% copper and weighs 25 pounds. A second alloy is 18% copper. How... (answered by checkley77)

A broze alloy is made of copper and tin. A company has 20 pounds of a bronze alloy that... (answered by lwsshak3)