document.write( "Question 60: Afreight train and an express train leave towns 390km apart, traveling toward one another. The freight train travels 30km per hr slower than the express train. They pass another 3 hr. later. What are their speeds! \n" ); document.write( "

Algebra.Com's Answer #728128 by amalm06(224) $\"\"$ $\"About$

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Distance traveled by express train: De/dt=r --> De=r dt (1)
\n" ); document.write( "Distance traveled by freight train: Df/dt=r-30 --> Df= r-30 dt (2)\r
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\n" ); document.write( "\n" ); document.write( "Solve (1) and (2) as follows:\r
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\n" ); document.write( "\n" ); document.write( "De = $\"int%28r%2C+dt%2C+0%2C+3%29\"$ = 3r\r
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\n" ); document.write( "\n" ); document.write( "Df = $\"int%28r-30%2C+dt%2C+0%2C+3%29\"$ = 3r-90\r
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\n" ); document.write( "\n" ); document.write( "The total distance traveled is 390 km:\r
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\n" ); document.write( "\n" ); document.write( "3r+3r-90=390\r
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\n" ); document.write( "\n" ); document.write( "6r-90=390\r
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\n" ); document.write( "\n" ); document.write( "6r=480\r
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\n" ); document.write( "\n" ); document.write( "r=80 km/hr, 50 km/hr (Answer) \r
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