document.write( "Question 392246: sir pls help me to solve this prblm.A train travels at a certain average for a didtance of 63km and then travels a distance of 72km at an average speed of 6km/hr more than its original speed.if it takes 3 hours to complete the total journey,what is its original average speed.kindly send me the solution to rexi_2004@yahoo.co.in \n" ); document.write( "
Algebra.Com's Answer #278415 by stanbon(75887)\"\" \"About 
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A train travels at a certain average for a distance of 63km and then travels a distance of 72km at an average speed of 6km/hr more than its original speed.
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\n" ); document.write( "\n" ); document.write( "If it takes 3 hours to complete the total journey,what is its original average speed.
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\n" ); document.write( "Original-speed DATA:
\n" ); document.write( "distance = 63 km ; rate = x km/hr ; time = 63/x hrs.
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\n" ); document.write( "Faster-speed DATA:
\n" ); document.write( "distance = 72 km ; rate = (x+6)km/hr ; time = 72/(x+6) hrs.
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\n" ); document.write( "Equation:
\n" ); document.write( "time + time = 3 hrs
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\n" ); document.write( "63/x + 72/(x+6) = 3 hrs
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\n" ); document.write( "63(x+6) + 72x = 3x(x+6)
\n" ); document.write( "21(x+6) + 24x = x(x+6)
\n" ); document.write( "45x + 21*6 = x^2+6x
\n" ); document.write( "x^2-39x-21*6 = 0
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\n" ); document.write( "x^2-39x-126 = 0
\n" ); document.write( "(x-42)(x+3) = 0
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\n" ); document.write( "Positive solution:
\n" ); document.write( "x = 42 km/hr (original rate)
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H. \n" ); document.write( "
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