document.write( "Question 408008: A car averaged 40 mph for part of a trip and 50 mph for the remainer. If the 5-hour trip covered 210 miles, for how long did the car average 40 mph? \n" ); document.write( "
Algebra.Com's Answer #287490 by ankor@dixie-net.com(22740)\"\" \"About 
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A car averaged 40 mph for part of a trip and 50 mph for the remainder.
\n" ); document.write( "If the 5-hour trip covered 210 miles, for how long did the car average 40 mph?
\n" ); document.write( ":
\n" ); document.write( "Let t = time at 40 mph
\n" ); document.write( "then, since the total time was 5 hrs:
\n" ); document.write( "(5-t) = time at 50 mph
\n" ); document.write( ":
\n" ); document.write( "Write a dist equation: Dist = speed * time
\n" ); document.write( "40t + 50(5-t) = 210
\n" ); document.write( "40t + 250 - 50t = 210
\n" ); document.write( "40t - 50t = 210 - 250
\n" ); document.write( "-10t = -40
\n" ); document.write( "t = \"%28-40%29%2F%28-10%29\"
\n" ); document.write( "t = +4 hrs at 40 mph
\n" ); document.write( ":
\n" ); document.write( ":
\n" ); document.write( "Check the solution by finding the dist at each speed (5-4 = 1 hr at 50mph)
\n" ); document.write( "4(40) + 1(50) =
\n" ); document.write( "160 + 50 = 210 \n" ); document.write( "
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