document.write( "Question 635043: Karen traveled 640 miles by boat and returned by plane. She spent 42 hours traveling on the trip. If the rate of the plane is 20 times faster than the rate of the boat, find each rate. \n" ); document.write( "

Algebra.Com's Answer #400048 by ankor@dixie-net.com(22740) $\"\"$ $\"About$

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Karen traveled 640 miles by boat and returned by plane.
\n" ); document.write( "She spent 42 hours traveling on the trip.
\n" ); document.write( " If the rate of the plane is 20 times faster than the rate of the boat, find each rate.
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\n" ); document.write( "Let r = speed of the boat
\n" ); document.write( "then
\n" ); document.write( "20r = speed of the plane
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\n" ); document.write( "Write a time equation; time = dist/speed
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\n" ); document.write( "boat time + plane time = 42 hrs
\n" ); document.write( " $\"640%2Fr\"$ + $\"640%2F%2820r%29\"$ = 42
\n" ); document.write( "reduce the fraction, divide 20 into 640
\n" ); document.write( " $\"640%2Fr\"$ + $\"32%2Fr\"$ = 42
\n" ); document.write( " $\"672%2Fr\"$ = 42
\n" ); document.write( "42r = 672
\n" ); document.write( "r = 672/42
\n" ); document.write( "r = 16 mph, boat speed
\n" ); document.write( "then
\n" ); document.write( "20(16) = 320 mph is the plane speed
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\n" ); document.write( "Confirm this find the travel time of each
\n" ); document.write( "640/16 = 40 hrs
\n" ); document.write( "640/320 = 2 hrs
\n" ); document.write( "-----------------
\n" ); document.write( "totals: 42 hrs
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