document.write( "Question 1163838: A and B build a road. A alone needs 40 days. B alone needs 24 days. A and B start from the opposite ends and work to the middle. They met at a point that is 750 meters from the center point of the road. How long is the road? \n" ); document.write( "

Algebra.Com's Answer #788076 by ikleyn(53937) $\"\"$ $\"About$

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document.write( "Let d be the length of the road (the unknown value under the problem's question).\r\n" );
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document.write( "The rate of A is    of the road length per day;  rate of B is    of the road length per day.\r\n" );
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document.write( "Their combined rate working together is then   +  =  =  =   of the road per day.\r\n" );
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document.write( "So, they complete their job in 15 days working together.\r\n" );
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document.write( "In 15 days, A will build  ;  B will build  .\r\n" );
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document.write( "From the condition, we have this equation\r\n" );
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document.write( "     -  = 2*750 = 1500  meters.\r\n" );
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document.write( "Multiply both sides by 120.  You will get then\r\n" );
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document.write( "    15*5d - 15*3d = 1500*120\r\n" );
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document.write( "    75d   - 45d   = 1500*120\r\n" );
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document.write( "    30d           = 1500*120\r\n" );
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document.write( "       d          =  = 50*120 = 6000 meters.\r\n" );
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