document.write( "Question 1040754: 1. Anne and Nancy use a metal mixture that is 20% copper to make jewelry. How many ounces of a 14% alloy must be mixed with a 23% alloy to form 69 ounces of the desired alloy?\r
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\n" ); document.write( "\n" ); document.write( "2. A cruise boat travels 36 miles downstream in 3 hours and returns to its starting point in 12 hours. Find the speed of the stream? \n" ); document.write( "
Algebra.Com's Answer #655643 by stanbon(75887)\"\" \"About 
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1. Anne and Nancy use a metal mixture that is 20% copper to make jewelry. How many ounces of a 14% alloy must be mixed with a 23% alloy to form 69 ounces of the desired alloy?
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\n" ); document.write( "copper + copper = copper
\n" ); document.write( "0.14x + 0.23(69-x) = 0.20*69
\n" ); document.write( "14x + 23*69 - 23x = 20*69
\n" ); document.write( "-9x = -3*69
\n" ); document.write( "x = 23 oz (amt. of 14% needed)
\n" ); document.write( "69-x = 46 oz (amt. of 23% needed)
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\n" ); document.write( "\n" ); document.write( "2. A cruise boat travels 36 miles downstream in 3 hours and returns to its starting point in 12 hours. Find the speed of the stream?
\n" ); document.write( "downstream DATA:
\n" ); document.write( "dist = 36 miles ; time = 3 hrs ; rate = 36/3 = 12 mph
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\n" ); document.write( "upstream DATA:
\n" ); document.write( "dist = 36 miles ; time = 12 hrs ; rate = 36/12 = 3 mph
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\n" ); document.write( "b + s = 12 mph
\n" ); document.write( "b - s = 3 mph
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\n" ); document.write( "2b = 15 mph
\n" ); document.write( "boat speed = 7.5 mph
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\n" ); document.write( "s = 12-b = 4.5 mph (stream speed)
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
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