document.write( "Question 210731: As Kayla leaves the gym for a 12 mile run. She starts her run on level terrain where she can run at 8 miles per hour. Then her path becomes hilly and she can only run at 4 miles per hour. Find the amount of time she runs at each speeds if her total running time is 2 hours and 20 minutes. \n" ); document.write( "
Algebra.Com's Answer #159199 by stanbon(75887)\"\" \"About 
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As Kayla leaves the gym for a 12 mile run. She starts her run on level terrain where she can run at 8 miles per hour. Then her path becomes hilly and she can only run at 4 miles per hour. Find the amount of time she runs at each speeds if her total running time is 2 hours and 20 minutes.
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\n" ); document.write( "Level DATA:
\n" ); document.write( "rate = 8 mph ; distance = x miles ; time = d/r = x/8 hrs.
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\n" ); document.write( " Hilly DATA:
\n" ); document.write( "rate = 4 mph ; distance = (12-x) miles ; time = (12-x)/4 hrs
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\n" ); document.write( "Equation:
\n" ); document.write( "time + time = 2 1/3 hrs
\n" ); document.write( "x/8 + (12-x)/4 = 7/3
\n" ); document.write( "----
\n" ); document.write( "3x + 6(12-x) = 8*7
\n" ); document.write( "3x + 72 - 6x = 56
\n" ); document.write( "-3x = -16
\n" ); document.write( "x = 16/3 miles (distance run on the level)
\n" ); document.write( "---
\n" ); document.write( "Time on level ground: (16/3)/8 = 2/3 hr.
\n" ); document.write( "Time on hilly ground: (7/3)-(2/3) = 4/3 hr.
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H. \n" ); document.write( "
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