document.write( "Question 733323: I am responsible for defending two bicycle cyclists who have been accused of “speeding.” I
\n" ); document.write( "say “speeding” because in one of these towns the law is quite peculiar. A tram runs from the valley of East
\n" ); document.write( "Gausston to the city center of Eulerberg. The travel time from the valley to the city is 40 minutes and a tram
\n" ); document.write( "leaves on the hour every hour between 8 a.m. and 3 p.m. The law here states that no vehicles (including
\n" ); document.write( "bicycles) can make the trip from East Gausston to Eulerberg in less time than it takes the tram. (Some
\n" ); document.write( "suspect that the city council is acting to protect the financial interests of Big Tram). These are the facts
\n" ); document.write( "of the case: My client was invited to Eulerberg to receive an award for her community service efforts. She
\n" ); document.write( "left her home in East Gausston in the afternoon on her bicycle. Her bicycle is equipped with a speedometer.
\n" ); document.write( "For the first 5 km she travelled on constant rate of 25 km/hour, then she came to a hill where her speed
\n" ); document.write( "immediately dropped to a constant rate of 15 km/hour as she climbed the 5 km hill. After she reached the
\n" ); document.write( "top she was able to ride at a constant rate of 35 km/hour for the final 5 km to the city center. During her
\n" ); document.write( "acceptance speech she showed the group the readings from her speedometer to illustrate that bicycling is a
\n" ); document.write( "fantastic alternative to driving. After the party she was ticketed for speeding by a local official. He asserts
\n" ); document.write( "that her average speed was 25 km/hour (averaging her three speeds) and therefore, that it must have taken
\n" ); document.write( "her 36 minutes to traverse the 15 km from her house to the city center. Since this is less than the 40 minutes
\n" ); document.write( "the tram takes, she is guilty of speeding. My client says that the trip actually took just over 40 minutes.
\n" ); document.write( "How can this be? Please help me to provide an airtight defense or tell me if I should take the plea deal
\n" ); document.write( "instead. I either need to convince the local jurist that she did not speed or convince her that I know she did.
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Algebra.Com's Answer #448356 by josmiceli(19441)\"\" \"About 
You can put this solution on YOUR website!
You cannot take an average of average speeds to get
\n" ); document.write( "a combined average.
\n" ); document.write( "average speed = ( total distance ) / ( total time )
\n" ); document.write( "For the first 5 km she travelled on constant rate of 25 km/hour
\n" ); document.write( "\"+5+=+25%2At+\"
\n" ); document.write( "\"+t+=+1%2F5+\" hr
\n" ); document.write( "Then she traveled at constant rate of 15 km/hour as she climbed the 5 km hill
\n" ); document.write( "\"+5+=+15%2At+\"
\n" ); document.write( "\"+t+=+1%2F3+\" hr
\n" ); document.write( "She rode down the hill at a constant rate of 35 km/hour for the 5 km trip to the city center.
\n" ); document.write( "\"+5+=+35%2At+\"
\n" ); document.write( "\"+t+=+1%2F7+\" hr
\n" ); document.write( "-------------
\n" ); document.write( "Total distance traveled was \"+3%2A5+=+15+\" km
\n" ); document.write( "Total time for trip was \"+1%2F5+%2B+1%2F3+%2B+1%2F7+\" hrs
\n" ); document.write( "\"+21%2F105+%2B+35%2F105+%2B+15%2F105+=+71%2F105+\"
\n" ); document.write( "The total time for the trip was \"+71%2F105+=+.676+\" hrs
\n" ); document.write( "\"+.676%2A60+=+40.57+\" min
\n" ); document.write( "The is more than the 40 min for the tram, so she wasn't speeding\r
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