document.write( "Question 317173: The river is flowing from point A to B at a rate of 15 miles per hour. A boat moves on still water at 45 miles per hour. If it takes David 1 hour and 15 minutes to ride the boat on the river from A to B, how long does it take him to make the return trip from B to A? \n" ); document.write( "

Algebra.Com's Answer #227194 by ankor@dixie-net.com(22740) $\"\"$ $\"About$

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The river is flowing from point A to B at a rate of 15 miles per hour.
\n" ); document.write( " A boat moves on still water at 45 miles per hour.
\n" ); document.write( " If it takes David 1 hour and 15 minutes to ride the boat on the river from A
\n" ); document.write( " to B, how long does it take him to make the return trip from B to A?
\n" ); document.write( ":
\n" ); document.write( "Let t = time in hrs to go from B to A
\n" ); document.write( ":
\n" ); document.write( "change 1 hr 15 min to 1.25 hrs
\n" ); document.write( ":
\n" ); document.write( "Write a distance equation: dist = speed * time
\n" ); document.write( ":
\n" ); document.write( "A-B dist = B-A dist
\n" ); document.write( "1.25(45+15) = t(45-15)
\n" ); document.write( "1.25(60) = 30t
\n" ); document.write( "75 = 30t
\n" ); document.write( "t = $\"75%2F30\"$
\n" ); document.write( "t = 2.5 hrs
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\n" ); document.write( ":
\n" ); document.write( "Check solution by finding the distances
\n" ); document.write( "1.25(60) = 75
\n" ); document.write( "2.5(30) = 75
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