document.write( "Question 192839: A bus traveled on a straight road for 2 hours at an average speed that was 20 mph faster than its average speed on a winding road.The time spent on the winding road was 3 hours. Find the average speed on the winding if the total trip was 210 miles. \n" ); document.write( "

Algebra.Com's Answer #144742 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"s%5Bw%5D\"$ = the average speed on the winding road
\n" ); document.write( "given:
\n" ); document.write( " $\"d%5Bs%5D+=+s%5Bs%5D%2At%5Bs%5D\"$
\n" ); document.write( " $\"d%5Bw%5D+=+s%5Bw%5D%2At%5Bw%5D\"$
\n" ); document.write( " $\"d%5Bs%5D+%2B+d%5Bw%5D+=+210\"$
\n" ); document.write( " $\"t%5Bs%5D+=+2\"$ hr
\n" ); document.write( " $\"t%5Bw%5D+=+3\"$ hr
\n" ); document.write( " $\"s%5Bs%5D+=+s%5Bw%5D+%2B+20\"$
\n" ); document.write( "----------------
\n" ); document.write( " $\"d%5Bs%5D+=+s%5Bs%5D%2A2\"$
\n" ); document.write( " $\"210+-+d%5Bs%5D+=%28+s%5Bs%5D+-+20%29%2A3\"$
\n" ); document.write( " $\"210+-+2s%5Bs%5D+=+3s%5Bs%5D+-+60\"$
\n" ); document.write( " $\"5s%5Bs%5D+=+270\"$
\n" ); document.write( " $\"s%5Bs%5D+=+54\"$ mi/hr
\n" ); document.write( "and, since
\n" ); document.write( " $\"s%5Bs%5D+=+s%5Bw%5D+%2B+20\"$
\n" ); document.write( " $\"54+=+s%5Bw%5D+%2B+20\"$
\n" ); document.write( " $\"s%5Bw%5D+=+34\"$ mi/hr
\n" ); document.write( "The average speed on the winding road was 34 mi/hr
\n" ); document.write( "check answer:
\n" ); document.write( " $\"d%5Bs%5D+=+s%5Bs%5D%2At%5Bs%5D\"$
\n" ); document.write( " $\"d%5Bs%5D+=+54%2A2\"$
\n" ); document.write( " $\"d%5Bs%5D+=+108\"$ mi
\n" ); document.write( "and
\n" ); document.write( " $\"d%5Bw%5D+=+s%5Bw%5D%2At%5Bw%5D\"$
\n" ); document.write( " $\"d%5Bw%5D+=+34%2A3\"$
\n" ); document.write( " $\"d%5Bw%5D+=+102\"$ mi
\n" ); document.write( "and
\n" ); document.write( " $\"108+%2B+102+=+210\"$ mi
\n" ); document.write( "OK \n" ); document.write( "

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