<PRE><B>Question 243473</B>
A goldsmith has two alloys that are different purities of gold. The first is three-fourths pure gold and the second is five-twelfths pure gold. How many ounces of each should be melted and mixed in order to obtain a 6-oz mixture that is two-thirds pure gold? 
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Equation:
gold + gold = gold
(3/4)x + (5/12)(12-x) = (2/3)12
Multiply thru by 12 to get:
9x + 5*12- 5x = 8*12
4x = 3^12
x = 9 oz (amt. of (3/4) alloy needed in the mix)
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12 - x = 12-9 = 3 oz (amt of (5/12) alloy needed in the mix)
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Cheers,
Stan H.
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