document.write( "Question 382246: a truck enters a highway driving 60 mph. A car enters the highway at the same place 7 minutes later and drives 71 mph in the same direction. from the time the car enters the highway, how long will it take the care to pass the truck?\r
\n" ); document.write( "\n" ); document.write( "Work:
\n" ); document.write( "Truck- d=60x r=60 t=x
\n" ); document.write( "Car- d= 71(x-7/60) r=71 t=(x-7/60)\r
\n" ); document.write( "\n" ); document.write( "60x=71(x-7/60)
\n" ); document.write( "60x=71x-497/60
\n" ); document.write( "60x71x= -497/60
\n" ); document.write( "-11x= -497/60
\n" ); document.write( "x= (-497/60)/-11
\n" ); document.write( "x= 497/660
\n" ); document.write( "x= 45 \r
\n" ); document.write( "\n" ); document.write( "But i have the answer and its 38 minutes...What am i doing wrong? \n" ); document.write( "

Algebra.Com's Answer #270975 by Alan3354(69443) $\"\"$ $\"About$

You can put this solution on YOUR website!
a truck enters a highway driving 60 mph. A car enters the highway at the same place 7 minutes later and drives 71 mph in the same direction. from the time the car enters the highway, how long will it take the care to pass the truck?
\n" ); document.write( "----------------
\n" ); document.write( "60 mph = 1 mile per minute so the truck is 7 miles ahead
\n" ); document.write( "The car gains on the truck at 11 mph (71-60)
\n" ); document.write( "It will take 7/11 hours to overtake the truck
\n" ); document.write( "= 7*60/11 minutes
\n" ); document.write( "=~ 38 minutes
\n" ); document.write( "----------------
\n" ); document.write( "Your solution of 45 minutes is the time starting when the truck entered the highway.
\n" ); document.write( " \n" ); document.write( "

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