document.write( "Question 178070: KWAN HIKED UP A HILL AT 4 km AND BACK DOWN AT 6 km HIS TOTAL HIKING TIME IS 3 HRS.HOW LONG DID THE TRIP UPHILL TAKE HIM? \n" ); document.write( "
Algebra.Com's Answer #133040 by josmiceli(19441)\"\" \"About 
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The distance is the same going up and down
\n" ); document.write( "\"d+=+r%5Bu%5D%2At%5Bu%5D\"
\n" ); document.write( "\"d+=+r%5Bd%5D%2At%5Bd%5D\"
\n" ); document.write( "given:
\n" ); document.write( "\"r%5Bu%5D+=+4\"km/hr
\n" ); document.write( "\"r%5Bd%5D+=+6\"km/hr
\n" ); document.write( "\"t%5Bu%5D+%2B+t%5Bd%5D+=+3\"hrs
\n" ); document.write( "\"d+=+4%2At%5Bu%5D\"
\n" ); document.write( "\"d+=+6%2At%5Bd%5D\"
\n" ); document.write( "I can set the right sides equal to eachother
\n" ); document.write( "\"4%2At%5Bu%5D+=+6%2At%5Bd%5D\"
\n" ); document.write( "\"t%5Bu%5D+=+%283%2F2%29%2At%5Bd%5D\"
\n" ); document.write( "And, since
\n" ); document.write( "\"t%5Bu%5D+%2B+t%5Bd%5D+=+3\"
\n" ); document.write( "\"%283%2F2%29%2At%5Bd%5D+%2B+t%5Bd%5D+=+3\"
\n" ); document.write( "\"3t%5Bd%5D+%2B+2t%5Bd%5D+=+6\"
\n" ); document.write( "\"5t%5Bd%5D+=+6\"
\n" ); document.write( "\"t%5Bd%5D+=+6%2F5\"hrs
\n" ); document.write( "and
\n" ); document.write( "\"t%5Bu%5D+=+%283%2F2%29%2At%5Bd%5D\"
\n" ); document.write( "\"t%5Bu%5D+=+%283%2F2%29%2A%286%2F5%29\"
\n" ); document.write( "\"t%5Bu%5D+=+9%2F5\"hrs
\n" ); document.write( "The uphill trip took 1 hr and 4/5 of an hr, or
\n" ); document.write( "1 hr and 48 minutes
\n" ); document.write( "check:
\n" ); document.write( "\"d+=+r%5Bu%5D%2At%5Bu%5D\"
\n" ); document.write( "\"d+=+4%2A%289%2F5%29\"
\n" ); document.write( "\"d+=+36%2F5\"
\n" ); document.write( "------------------
\n" ); document.write( "\"d+=+r%5Bd%5D%2At%5Bd%5D\"
\n" ); document.write( "\"d+=+6%2A%286%2F5%29\"
\n" ); document.write( "\"d+=+36%2F5\"
\n" ); document.write( "The distances are equal as they should be, and
\n" ); document.write( "\"6%2F5+%2B+9%2F5+=+3\", the total time is 3 hrs \n" ); document.write( "
\n" );