document.write( "Question 1184521: Please help me solve this question.
\n" ); document.write( "John leaves his house at 7:00 am. His sister, Mary leaves the house at 8:30 am and tries to catch up with John. She is walking 2 km/h faster than him on the same route in the same direction. If they both kept in the same route, Mary could reach John 3 hours after she left. Find John and Mary’s speed. \n" ); document.write( "
Algebra.Com's Answer #815133 by mccravyedwin(407)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "John's rate = r\r\n" );
document.write( "Mary's rate = r+2\r\n" );
document.write( "Mary's time till they meet = 3  \r\n" );
document.write( "John's time till they meet = 4.5 (7:00 am to 8:30 is an hour and a half,\r\n" );
document.write( "                                  and 3+1.5 = 4.5\r\n" );
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document.write( "       rate  x  time  =  distance\r\n" );
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document.write( "John     r      4.5    =   4.5r\r\n" );
document.write( "Mary    r+2      3   =    3(r+2)      \r\n" );
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document.write( "The distances are equal, so\r\n" );
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document.write( "4.5r = 3(r+2)\r\n" );
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document.write( "Multiply both sides by 10 to clear the decimal\r\n" );
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document.write( "45r = 30(r+2)\r\n" );
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document.write( "Divide both sides by 15\r\n" );
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document.write( "3r = 2(r+2)\r\n" );
document.write( "3r = 2r+4\r\n" );
document.write( " r = 4 km/h = John's rate.\r\n" );
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document.write( "Mary's rate = 2 km/h + 2 km/h = 4 km/h\r\n" );
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document.write( "Edwin
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