Answer:
1800 oz.
Step-by-step explanation:
There are already 600 ounces of alloy of nickel.
Of this 600 oz, 50% is pure i.e. copper content = 600(0.5) = 300 oz
Now available is
Copper Other metals
300 300
Let x oz of 10% copper is added.
Then new alloy will have 300+0.1x oz copper in total of 600+x oz.
Percentage pure = [tex]\frac{300+0.1x}{600+x} =20%[/tex]
Simplify to get
[tex]\frac{300+0.1x}{600+x} =\frac{20}{100} \\\\Cross multiply:\\20(600+x) =100(300+0.1x)\\12000+20x =30000+10x\\10x = 18000\\x = 1800[/tex]
Hence answer is 1800 oz should be added.
