document.write( "Question 278480: Caleb's average speed is 12 kilometers per hour slower than Ling's. In the same length of time it takes Caleb to drive 231 km, Ling drives 297 km. What is Caleb's average speed? \n" ); document.write( "
Algebra.Com's Answer #202643 by stanbon(75887)\"\" \"About 
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Caleb's average speed is 12 kilometers per hour slower than Ling's. In the same length of time it takes Caleb to drive 231 km, Ling drives 297 km. What is Caleb's average speed?
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\n" ); document.write( "Ling DATA:
\n" ); document.write( "rate = x kmh ; distance = 297 km ; time = 297/x hr
\n" ); document.write( "-----------------------
\n" ); document.write( "Caleb DATA:
\n" ); document.write( "rate = (x-12)kmh ; distance = 231 km ; time = 231/(x-12) hr
\n" ); document.write( "-----------------------
\n" ); document.write( "Equation:
\n" ); document.write( "time = time
\n" ); document.write( "297/x = 231/(x-12)
\n" ); document.write( "Cross-multiply:
\n" ); document.write( "287x - 297*12 = 231x
\n" ); document.write( "56x = 3564
\n" ); document.write( "x = 63.64 kmh
\n" ); document.write( "---
\n" ); document.write( "Caleb speed = x-12 = 51.64 kmh
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H. \n" ); document.write( "
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