document.write( "Question 1154837: A long-distance runner starts on a course running at an average speed of 6mph. Half an hour later, a second runner begins the same course at an average speed of 7mph. How long after the second runner starts will the second runner overtake the first runner? \n" ); document.write( "
Algebra.Com's Answer #777332 by greenestamps(13200)\"\" \"About 
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\n" ); document.write( "The second runner starts a half hour after the first. Since the first runner runs at 6mph, he has run 3 miles when the second runner starts.

\n" ); document.write( "The second runner runs 1mph faster than the first. The amount of time he needs to make up the 3 miles, at the rate of 1mph, is 3 hours.

\n" ); document.write( "ANSWER: 3 hours

\n" ); document.write( "Algebraically....:

\n" ); document.write( "x = hours the second runner runs
\n" ); document.write( "x+0.5 = hours the first runner runs

\n" ); document.write( "7x = distance second runner runs
\n" ); document.write( "6(x+0.5) = distance first runner runs.

\n" ); document.write( "\"7x+=+6%28x%2B0.5%29\"
\n" ); document.write( "\"7x+=+6x%2B3\"
\n" ); document.write( "\"x+=+3\"

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