document.write( "Question 291936: Jack and Susan participated in the New York City Marathon. They each maintained a constant pace for the first hour. Find, in mph, how much faster Jack was running than Susan if at 4 miles Jack was and 40 minutes and if Susan was at 3 miles in 40 minutes. \n" ); document.write( "

Algebra.Com's Answer #210988 by oberobic(2304) $\"\"$ $\"About$

You can put this solution on YOUR website!
I was confused by your description, but I think you mean:
\n" ); document.write( "Jack ran 4 miles in 40 minutes, and Susan ran 3 miles in 40 minutes.
\n" ); document.write( "The task thus becomes one of converting to miles per hour and comparing them.
\n" ); document.write( "We know 60 minutes = 1 hr, so 40 minutes = 40/60 = 2/3 hr.
\n" ); document.write( "We also know the distance formula: d = rt.
\n" ); document.write( ".
\n" ); document.write( "J = Jack's speed
\n" ); document.write( "S = Susan's speed
\n" ); document.write( ".
\n" ); document.write( "4 = J*2/3
\n" ); document.write( "6 = J
\n" ); document.write( "Jack is running at 6 miles/hr.
\n" ); document.write( ".
\n" ); document.write( "3 = S*2/3
\n" ); document.write( "4.5 = S
\n" ); document.write( "Susan is running at 4.5 miles/hr.
\n" ); document.write( ".
\n" ); document.write( "How much faster is Jack running than Susan?
\n" ); document.write( "1.5 miles/hr
\n" ); document.write( ".
\n" ); document.write( "Checking, how far would each run in 1 hr?
\n" ); document.write( "d = 6*1
\n" ); document.write( "Jack runs 6 miles
\n" ); document.write( "d = 4.5*1
\n" ); document.write( "Susan runs 4.5 miles
\n" ); document.write( "Checks.
\n" ); document.write( ".
\n" ); document.write( "Done. \n" ); document.write( "

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