document.write( "Question 1208606: Every day Jane and Bill both drive into a parking lot, and then take a subway to get to work. Jane drives 22km at 50km/h, and then takes a northbound subway that averages 30 km/h for 14 km, while Bill drives 30 km at 60 km/h and then takes a southbound subway that averages 20km/h for 6 km. It takes each of them 10 minutes to change from car to subway, and they arrive at the same destination at 8:30 a.m. At what time, to the nearest minute does the earliest of them leave home? \n" ); document.write( "

Algebra.Com's Answer #846970 by ikleyn(52772) $\"\"$ $\"About$

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\n" ); document.write( "Every day Jane and Bill both drive into a parking lot, and then take a subway to get to work.
\n" ); document.write( "Jane drives 22km at 50km/h, and then takes a northbound subway that averages 30 km/h for 14 km, while
\n" ); document.write( "Bill drives 30 km at 60 km/h and then takes a southbound subway that averages 20km/h for 6 km.
\n" ); document.write( "It takes each of them 10 minutes to change from car to subway, and they arrive at the same destination at 8:30 a.m.
\n" ); document.write( "At what time, to the nearest minute does the earliest of them leave home?
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document.write( "Jane's travel time is   +  + 10 = 64.4 minutes (including 10 minutes for change from car to subway).\r\n" );
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document.write( "Bill's travel time is   +  + 10 = 58 minutes (including 10 minutes for change from car to subway).\r\n" );
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document.write( "    (Everywhere, where you see 60 in the denominator, it is used to convert the speed from km/h to km/minute).\r\n" );
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document.write( "Jane's travel time is longer - hence, Jane leaves home earlier.\r\n" );
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document.write( "Jane leaves his home 64.4 minutes before 8:30 am, which is about 7:25 am.    ANSWER\r\n" );
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document.write( "The key for the solution is the formula  t = .\r\n" );
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document.write( "It says: to find the travel time, divide the distance by the speed.\r\n" );
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document.write( "So, we find the travel time for each part of the journey for each participant,\r\n" );
document.write( "knowing the length of every part and the speed (which speed we convert to km/minute, for convenience).\r\n" );
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\n" ); document.write( "\n" ); document.write( "Tutor @math_tutor2020 noticed my error in the formula, thanks for it.\r
\n" ); document.write( "\n" ); document.write( "So I fixed it, and now you see the corrected version.\r
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