document.write( "Question 88794: In a race , Mary is 50 ft. in front of Susie after 10 seconds. How fast can Mary run if Susie runs 20 ft per second? \n" ); document.write( "

Algebra.Com's Answer #64528 by bucky(2189) $\"\"$ $\"About$

You can put this solution on YOUR website!
The distance formula tells that Distance = Rate * Time.
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\n" ); document.write( "If Susie runs at 20 ft per second, then in 10 seconds she has run 200 ft. You can get this
\n" ); document.write( "from the Distance formula:
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\n" ); document.write( "Distance = 20 * 10 = 200
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\n" ); document.write( "But in that same 10 seconds Mary has run 50 feet more than Susie. So in 10 seconds Mary has run
\n" ); document.write( "250 feet.
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\n" ); document.write( "Now you can calculate Mary's Rate (which is her speed). You know the distance she ran was
\n" ); document.write( "250 feet and the time that she ran it in was 10 seconds. Substituting those values into the
\n" ); document.write( "distance formula gives you:
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\n" ); document.write( "250 = R * 10
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\n" ); document.write( "Solve for R by dividing both sides of this equation by 10 to get:
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\n" ); document.write( "R = 250/10 = 25 feet per second.
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\n" ); document.write( "So while Susie runs at a rate of 20 ft per second, Mary (who is faster) runs at a rate of
\n" ); document.write( "25 feet per second.
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\n" ); document.write( "Hope this helps you to understand the problem.
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