document.write( "Question 306365: Someone drove to the city at a rate of 50 km/h. He returned along the same route at a faster speed, making his average rate for the round trip 60 km/h.
\n" ); document.write( "What was his returning speed? \n" ); document.write( "

Algebra.Com's Answer #219268 by josmiceli(19441) $\"\"$ $\"About$

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Ave speed = (total distance)/(total time)
\n" ); document.write( "Let $\"d\"$ = distance to city
\n" ); document.write( "Let $\"s\"$ = his returning speed
\n" ); document.write( "given:
\n" ); document.write( " $\"d%2F50\"$ = time to get to city
\n" ); document.write( " $\"%28d+%2B+d%29%2F%28d%2F50+%2B+d%2Fs%29+=+60\"$
\n" ); document.write( " $\"2d+=+60%2A%28d%2F50+%2B+d%2Fs%29\"$
\n" ); document.write( " $\"2d+=+60d%281%2F50+%2B+1%2Fs%29\"$
\n" ); document.write( " $\"1%2F30+=+1%2F50+%2B+1%2Fs\"$
\n" ); document.write( "Multiply both sides by $\"150s\"$
\n" ); document.write( " $\"5s+=+3s+%2B+150\"$
\n" ); document.write( " $\"2s+=+150\"$
\n" ); document.write( " $\"s+=+75\"$
\n" ); document.write( "His return speed was 75 mi/hr \n" ); document.write( "

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