document.write( "Question 341266: in order to qualify for a race emily needs to go at an average speed of 100 mi/h for two laps. but she only goes 75mi/h on the first lap. How fast does she need to go on the second lap to reach the average speed of 100 mi/h? \n" ); document.write( "
Algebra.Com's Answer #244355 by stanbon(75887)\"\" \"About 
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in order to qualify for a race emily needs to go at an average speed of 100 mi/h for two laps. but she only goes 75mi/h on the first lap.
\n" ); document.write( "Let distance of a lap = x miles
\n" ); document.write( "If rate = 75 mph, time = x/75 hrs
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\n" ); document.write( "How fast does she need to go on the second lap to reach the average speed of 100 mi/h?
\n" ); document.write( "Distance for 2 laps = 2x miles
\n" ); document.write( "If rate = 100 mph, time = (2x)/100 = x/50 hrs
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\n" ); document.write( "Time for her 2nd lap would have to be time for 2 laps - time for 1st lap
\n" ); document.write( "x/50-x/75 = (75x-50x)/(50*75) = 25x/(50*75) = x/150 hrs.
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\n" ); document.write( "distance/time = rate
\n" ); document.write( "x/(x/150) = 150 mph
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\n" ); document.write( "She would have to go 150 mph to average 100 mph for the 2 laps.
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H. \n" ); document.write( "
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