document.write( "Question 171770This question is from textbook Algebra and Trigonometry: Structure and Method-Book 2
\n" ); document.write( ": The rail line between two cities consists of two segments, one 96 km longer than the other. A passenger train averages 60 km/h over the shorter segment, 120 km/h over the longer, and 100 km/h for the entire trip. How far apart are the cities? \n" ); document.write( "
Algebra.Com's Answer #127022 by ankor@dixie-net.com(22740)\"\" \"About 
You can put this solution on YOUR website!
The rail line between two cities consists of two segments, one 96 km longer
\n" ); document.write( " than the other. A passenger train averages 60 km/h over the shorter segment,
\n" ); document.write( " 120 km/h over the longer, and 100 km/h for the entire trip.
\n" ); document.write( " How far apart are the cities?
\n" ); document.write( ":
\n" ); document.write( "Let d = distance of the shorter segment (traveled at 60 km/hr)
\n" ); document.write( "and
\n" ); document.write( "(d+96) = distance of the longer segment (traveled at 120 km/hr)
\n" ); document.write( "then
\n" ); document.write( "2d + 96 = total distance between the two cities (average of 100 km/hr)
\n" ); document.write( ":
\n" ); document.write( "How about writing a time equation? Time = dist/speed:
\n" ); document.write( ":
\n" ); document.write( "\"d%2F60\" + \"%28%28d%2B96%29%29%2F120\" = \"%28%282d%2B96%29%29%2F100\"
\n" ); document.write( ":
\n" ); document.write( "Multiply equation by 600 to get rid of the denominators; results:
\n" ); document.write( "10d + 5(d+96) = 6(2d+96)
\n" ); document.write( ":
\n" ); document.write( "10d + 5d + 480 = 12d + 576
\n" ); document.write( ":
\n" ); document.write( "10d + 5d - 12d = 576 - 480
\n" ); document.write( ":
\n" ); document.write( "3d = 96
\n" ); document.write( "d = \"96%2F3\"
\n" ); document.write( "d = 32 km the shorter segment
\n" ); document.write( "and
\n" ); document.write( "32 + 96 = 128 km the longer segment
\n" ); document.write( "then
\n" ); document.write( "2(32) + 96 = 160 km the total distance
\n" ); document.write( ":
\n" ); document.write( ":
\n" ); document.write( "Check solution by finding the times
\n" ); document.write( "32/60 + 128/120 = 160/100
\n" ); document.write( ".5333 + 1.0667 = 1.6
\n" ); document.write( ":
\n" ); document.write( ":
\n" ); document.write( "Did this make sense to you?
\n" ); document.write( "
\n" );