document.write( "Question 80603: An engine being tested for fuel consumption was operated at two fixed settings. The first setting results in a fuel consumption of 1 gallon every 12 minutes. The second setting results in a fuel consumption of 1 gallon every 15 minutes. The test ran 5 hours and 22 gallons of fuel were consumed. For how many minutes was the first test on the first setting? \n" ); document.write( "
Algebra.Com's Answer #57809 by stanbon(75887)\"\" \"About 
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An engine being tested for fuel consumption was operated at two fixed settings. The first setting results in a fuel consumption of 1 gallon every 12 minutes. The second setting results in a fuel consumption of 1 gallon every 15 minutes. The test ran 5 hours and 22 gallons of fuel were consumed. For how many minutes was the first test on the first setting?
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\n" ); document.write( "Let \"x\" minutes be be running time for the 1st setting;
\n" ); document.write( "# of gallons consumed will be x/12
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\n" ); document.write( "Then \"300-x\" will be the running time for the 2nd setting:
\n" ); document.write( "# of gallons consumes will be (300-x)/15
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\n" ); document.write( "EQUATION:
\n" ); document.write( "gallons + gallons = 22
\n" ); document.write( "x/12 + (300-x)/15 = 22
\n" ); document.write( "Multiply thru by 60 to get:
\n" ); document.write( "5x + 1200-4x = 60*22
\n" ); document.write( "x=1320-1200
\n" ); document.write( "x=120 minutes (time the 1st setting was used)
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
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