document.write( "Question 249425: An old car has to travel a 2-mile route, uphill and down. Because it is so old, the car can climb the first mile-the ascent-no faster than an average speed of 15 mi/h. How fast does the car have to travel the second-on the descent it can go faster, or course-in order to achieve an average speed of 30 mi/h for the trip? \n" ); document.write( "

Algebra.Com's Answer #181689 by ankor@dixie-net.com(22740) $\"\"$ $\"About$

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An old car has to travel a 2-mile route, uphill and down.
\n" ); document.write( " Because it is so old, the car can climb the first mile-the ascent-no faster than an average speed of 15 mi/h.
\n" ); document.write( "How fast does the car have to travel the second-on the descent it can go faster, or course-in order to achieve an average speed of 30 mi/h for the trip?
\n" ); document.write( ":
\n" ); document.write( "This is impossible; the time to go 1 mi at 15 mph, is the same as 2 mi at 30 mph
\n" ); document.write( "You have to go the 2nd mile in 0 time, that's fast!
\n" ); document.write( ":
\n" ); document.write( "But let's assume that it is a legitimate problem:
\n" ); document.write( ":
\n" ); document.write( "Let s = the speed down hill
\n" ); document.write( ":
\n" ); document.write( "Time up hill + time down hill = total time
\n" ); document.write( " $\"1%2F15\"$ + $\"1%2Fs\"$ = $\"2%2F30\"$
\n" ); document.write( ":
\n" ); document.write( "Multiply equation by 30s; results
\n" ); document.write( "2s + 30 = 2s
\n" ); document.write( ":
\n" ); document.write( "Obviously this is not possible \n" ); document.write( "

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