document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1157494>Question 1157494</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A pilot has a Cessna 172 Skyhawk airplane with a fuel tank that holds 56 gallons of 100LL fuel. The pilot charges his passenger $4.00 per gallon for the amount of old fuel that is already in the tank. The pilot then fills the rest of the tank with new fuel that costs $7.36 per gallon. The pilot bills the passenger $328.16 for the combined cost of the old fuel and new fuel. How many gallons of new fuel were required to fill the tank? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #780378 by </B><A HREF=/tutors/aboutme.mpl?userid=mathslover><B>mathslover(157)</B></A><img src=\"/images/stars/stars-09.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=mathslover><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=mathslover><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=780378\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Let the quantity of old fuel be x<BR>\n" );
document.write( "Quantity of new fuel be y \r<BR>\n" );
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document.write( "since total capacity of the tank is 56 <BR>\n" );
document.write( "=> x + y = 56   ..... (1)\r<BR>\n" );
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document.write( "Also , total cost of fuel\r<BR>\n" );
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document.write( "= 4x + 7.36y = 328.16  ....(2)\r<BR>\n" );
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document.write( "Multiplying equation (1) with 4 we get,<BR>\n" );
document.write( "  4x + 4y = 224  --------- (3)\r<BR>\n" );
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document.write( "Subtracting equation 3 from equation 2 we get,\r<BR>\n" );
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document.write( "3.36 y = 104.16 <BR>\n" );
document.write( "therefore y= 104.16/3.36 = 31\r<BR>\n" );
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document.write( "therefore new fuel is 31 gallon.<BR>\n" );
document.write( "Old fuel = 56 - 31 = 25 gallon\r<BR>\n" );
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document.write( "Ans: 31 gallons of new fuel were required to fill the tank. </SPAN>\n" );
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