document.write( "Question 520120: A train leaves Union Staion for Central Station, 216 km away, at 9:00 am. One hour later a train leaves Central Station for Union Station. They will meet at noon. If the second train had started at 9:00 am, and the first train at 10:30 am, they would still have met at noon. Find the speed of each train. \n" ); document.write( "
Algebra.Com's Answer #346000 by ankor@dixie-net.com(22740)\"\" \"About 
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A train leaves Union Station for Central Station, 216 km away, at 9:00 am.
\n" ); document.write( "One hour later a train leaves Central Station for Union Station.
\n" ); document.write( " They will meet at noon.
\n" ); document.write( " If the second train had started at 9:00 am, and the first train at 10:30 am, they would still have met at noon.
\n" ); document.write( " Find the speed of each train.
\n" ); document.write( ":
\n" ); document.write( "Let a = Train A's speed
\n" ); document.write( "Let b = Train B's speed
\n" ); document.write( ":
\n" ); document.write( "When they meet, the sum of their distances will equal 216 km
\n" ); document.write( "Write a distance equation for each Scenario
\n" ); document.write( ":
\n" ); document.write( "From the information given for the 1st scenario, travel times:
\n" ); document.write( "a = 3 hrs when they meet, b = 2 hrs when they meet
\n" ); document.write( "3a + 2b = 216 km
\n" ); document.write( ":
\n" ); document.write( "From the information given for the 2nd scenario, travel times:
\n" ); document.write( "a = 1.5 hrs when they meet, b = 3 hrs when they meet
\n" ); document.write( "1.5a + 3b = 216 km
\n" ); document.write( ":
\n" ); document.write( "Two equations we can solve
\n" ); document.write( "3a + 2b = 216
\n" ); document.write( "1.5a+3b = 216
\n" ); document.write( "multiply the 2nd equation by 2, subtract the 1st equation
\n" ); document.write( "3a + 6b = 432
\n" ); document.write( "3a + 2b = 216
\n" ); document.write( "---------------subtraction eliminates a, find b
\n" ); document.write( "4b = 216
\n" ); document.write( "b = 216/4
\n" ); document.write( "b = 54 km/h, speed of train B
\n" ); document.write( ":
\n" ); document.write( "Find a
\n" ); document.write( "3a + 2b = 216
\n" ); document.write( "3a + 2(54) = 216
\n" ); document.write( "3a = 216 - 108
\n" ); document.write( "3a = 108
\n" ); document.write( "a = 108/3
\n" ); document.write( "a = 36 km/h, speed of train A
\n" ); document.write( ":
\n" ); document.write( ":
\n" ); document.write( "You can check these solutions in both scenario equations.
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