<PRE><B>Question 825839</B>
A certain metal is 40% tin. How many kilograms of this metal must be mixed with 80 kilograms of a metal that is 70% tin to get a metal that is 50% tin?
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Equation:
tin + tin = tin
0.40x + 0.70*80 = 0.50(x+80)
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40x + 70*80 = 70x + 50*80
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-30x = -20*80
x = (2/3)80
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x = 53 1/3 kg (amt. of 40% metal needed)
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Cheers,
Stan H.
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