document.write( "Question 889613: A train running at 3 / 7 of its own speed reached the destination in 14 hours, how much time could be saved if the train would have run at its own speed ? \n" ); document.write( "

Algebra.Com's Answer #538293 by ankor@dixie-net.com(22740) $\"\"$ $\"About$

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train running at 3 / 7 of its own speed reached the destination in 14 hours,
\n" ); document.write( " how much time could be saved if the train would have run at its own speed ?
\n" ); document.write( ":
\n" ); document.write( "let s = normal speed of the train
\n" ); document.write( "let t = time required at normal speed
\n" ); document.write( ":
\n" ); document.write( "Write a dist equation, dist = speed * time
\n" ); document.write( " $\"3%2F7\"$ s*14 = s*t
\n" ); document.write( "multiply both sides by 7
\n" ); document.write( "3s*14 = 7st
\n" ); document.write( "divide both sides by s
\n" ); document.write( "3*14 = 7t
\n" ); document.write( "42 = 7t
\n" ); document.write( "t = 42/7
\n" ); document.write( "t = 6 hrs to make the trip at normal speed (they would save 8 hrs)
\n" ); document.write( ":
\n" ); document.write( ":
\n" ); document.write( "Check this using a normal speed of 70, (slow speed = 30)
\n" ); document.write( "should be the same dist
\n" ); document.write( "30*14 = 420 mi
\n" ); document.write( "70*6 = 420 mi \n" ); document.write( "

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