document.write( "Question 726240: Bill sets out to drive from Swansea to London. An hour after he'd started, he encountered heavy traffic and he was only able to drive at three-fifths of his former speed. He eventually arrived in London two hours later than he'd expected, and worked out that if he'd not met traffic until fifty miles further on he would have arrived in London forty minutes sooner. How far is it from Swansea to London? \n" ); document.write( "
Algebra.Com's Answer #444543 by josmiceli(19441)\"\" \"About 
You can put this solution on YOUR website!
Let \"+d+\" = distance from Swansea to London
\n" ); document.write( "Let \"+s+\" = his speed for the 1st hour
\n" ); document.write( "\"+d%5B1%5D+=+s%2A1+\"
\n" ); document.write( "\"+d%5B1%5D+=+s+\"
\n" ); document.write( "He now has a distance of \"+d+-+s+\" to go
\n" ); document.write( "He travels at \"+%283%2F5%29%2As+=+.6s+\"
\n" ); document.write( "for time = \"+t%5B1%5D+\"
\n" ); document.write( "\"+d+-+s+=+.6s%2At%5B1%5D+\"
\n" ); document.write( "\"+t%5B1%5D+=+%28+d+-+s+%29+%2F+%28+.6s+%29+\"
\n" ); document.write( "He eventually arrived in London two hours later than he'd expected
\n" ); document.write( "he would have got there when he expected if his speed was \"+s+\"
\n" ); document.write( "for the whole distance \"+d+\"
\n" ); document.write( "\"+d+=+s%2At%5B2%5D+\"
\n" ); document.write( "\"+t%5B2%5D+=+d%2Fs+\"
\n" ); document.write( "-------------
\n" ); document.write( "I can say:
\n" ); document.write( "\"+%28+d+-+s+%29+%2F+%28+.6s+%29+-+d%2Fs+=+2+\"
\n" ); document.write( "Multiply both sides by \"+.6s+\"
\n" ); document.write( "\"+d+-+s+-+.6d+=+2%2A%28+.6s+%29+\"
\n" ); document.write( "\"+.4d+=+1.2s+%2B+s+\"
\n" ); document.write( "\"+.4d+=+2.2s+\"
\n" ); document.write( "\"+d+=+2.2s+%2F+.4+\"
\n" ); document.write( "\"+d+=+5.5s+\"
\n" ); document.write( "------------
\n" ); document.write( "Meeting the traffic 50 further on means that he
\n" ); document.write( "would travel at a speed of \"+s+\" for
\n" ); document.write( "a distance = \"+s%2A1+%2B+50+\"
\n" ); document.write( "This is a time of \"+t%5B3%5D+=+%28+s+%2B+50+%29+%2F+s+\"
\n" ); document.write( "After the traffic, his time is \"+t%5B4%5D+=+%28+d+-+%28+s+%2B+50+%29+%29+%2F+%28+.6s+%29+\"
\n" ); document.write( "\"+t%5B3%5D+%2B+t%5B4%5D+=+%28+s+%2B+50+%29+%2F+s+%2B+%28+d+-+s+-+50+%29+%2F+%28+.6s+%29+\"
\n" ); document.write( "\"+t%5B3%5D+%2B+t%5B4%5D+=+%28+s+%2B+50+%29+%2F+s+%2B+%28+5.5s+-+s+-+50+%29+%2F+%28+.6s+%29+\"
\n" ); document.write( "\"+t%5B3%5D+%2B+t%5B4%5D+=+%28+s+%2B+50+%29+%2F+s+%2B+%28+4.5s+-+50+%29+%2F+%28+.6s+%29+\"
\n" ); document.write( "I am given that
\n" ); document.write( "\"+t%5B1%5D+-+%28+t%5B3%5D+%2B+t%5B4%5D+%29+=+2%2F3+\" ( 40 min is 2/3 hr )
\n" ); document.write( "\"+%28+d-s+%29%2F%28.6s%29+-+%28+s%2B50+%29+%2F+s+-+%28+4.5s+-+50+%29+%2F+%28.6s%29++=+2%2F3+\"
\n" ); document.write( "
\n" ); document.write( "\"+%28+4.5s+%29%2F%28.6s%29+-+%28+s%2B50+%29+%2F+s+-+%28+4.5s+-+50+%29+%2F+%28.6s%29++=+2%2F3+\"
\n" ); document.write( "Multiply both sides by \"+.6s+\"
\n" ); document.write( "\"+4.5s+-+.6%2A%28+s+%2B+50+%29+-+4.5s+%2B+50+=+%282%2F3%29%2A%28+.6s+%29+\"
\n" ); document.write( "Multiply both sides by \"+3+\"
\n" ); document.write( "\"+13.5s+-+1.8s+-+90+-+13.5s+%2B+150+=+1.2s+\"
\n" ); document.write( "\"+1.8s+%2B+1.2s+=+150+-+90+\"
\n" ); document.write( "\"+3s+=+60+\"
\n" ); document.write( "\"+s+=+20+\"
\n" ); document.write( "since \"+d+=+5.5s+\",
\n" ); document.write( "\"+d+=+5.5%2A20+\"
\n" ); document.write( "\"+d+=+110+\" answer
\n" ); document.write( "There are no units given, so I can't fill these in. ( km? )
\n" ); document.write( "Hope I got it\r
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