document.write( "Question 512601: A man walks six miles at four miles per hour. At what speed would he need to travel during the next two and a half hours to have an average speed of six miles an hour during the entire trip? \n" ); document.write( "

Algebra.Com's Answer #342666 by josmiceli(19441) $\"\"$ $\"About$

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Average speed is ( total distance ) / ( total time )
\n" ); document.write( "For the 1st 6 miles
\n" ); document.write( " $\"+6+=+4%2At+\"$
\n" ); document.write( " $\"+t+=+1.5+\"$ hrs
\n" ); document.write( "Let $\"+s+\"$ = speed for last $\"+2.5+\"$ hrs
\n" ); document.write( "--------------
\n" ); document.write( "Average speed = $\"+6+\"$ mi/hr
\n" ); document.write( "Total distance = $\"+6+%2B+2.5s+\"$
\n" ); document.write( " $\"+%28+6+%2B+2.5s+%29+%2F+%28+1.5+%2B+2.5+%29+=+6+\"$
\n" ); document.write( " $\"+%28+6+%2B+2.5s+%29+%2F+4+=+6+\"$
\n" ); document.write( " $\"+6+%2B+2.5s+=+24+\"$
\n" ); document.write( " $\"+2.5s+=+18+\"$
\n" ); document.write( " $\"+s+=+7.2+\"$
\n" ); document.write( "He would have to travel at 7.2 mi/hr
\n" ); document.write( " \n" ); document.write( "

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