document.write( "Question 635052: A tugboat goes 120 miles upstream in 20 hours. The return trip downstream takes 5 hours. Find the speed of the tug boat without a current , and with a current. \n" ); document.write( "
Algebra.Com's Answer #400056 by Maths68(1474)\"\" \"About 
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\n" ); document.write( "\n" ); document.write( "Speed of boat without current
\n" ); document.write( "----------------------------------
\n" ); document.write( "Time=t=20 hours
\n" ); document.write( "Speed of boat= s =
\n" ); document.write( "Distance = d = 120 miles
\n" ); document.write( "Speed of current = c
\n" ); document.write( "Distance=(Speed of boat - Speed of current) *time
\n" ); document.write( "120=(s-c)*20
\n" ); document.write( "120/20=s-c
\n" ); document.write( "6=s-c
\n" ); document.write( "s-c=6………………………….(1)\r
\n" ); document.write( "\n" ); document.write( "Speed of boat with the current
\n" ); document.write( "----------------------------------
\n" ); document.write( "Time=t=5 hours
\n" ); document.write( "Speed = s =
\n" ); document.write( "Distance = d = 120 miles
\n" ); document.write( "Speed of current = c
\n" ); document.write( "Distance=(Speed of boat+ Speed of current) *time
\n" ); document.write( "120=(s+c)*5
\n" ); document.write( "120/5=s+c
\n" ); document.write( "24=s+c
\n" ); document.write( "s+c=24………………………………………(2)\r
\n" ); document.write( "\n" ); document.write( "Add (1) and (2)
\n" ); document.write( "s-c=6……………………………………….(1)
\n" ); document.write( "s+c=24………………………………………(2)
\n" ); document.write( "--------------------
\n" ); document.write( "2s=30
\n" ); document.write( "s=30/2
\n" ); document.write( "s=15\r
\n" ); document.write( "\n" ); document.write( "Speed of boat is 15miles/hour.\r
\n" ); document.write( "\n" ); document.write( "Put the value of s in (1)
\n" ); document.write( "s-c=6……………………………………….(1)
\n" ); document.write( "15-c=6
\n" ); document.write( "-c=6-15
\n" ); document.write( "-c=-9
\n" ); document.write( "c=9\r
\n" ); document.write( "\n" ); document.write( "Speed of current is 9miles/hour.\r
\n" ); document.write( "\n" ); document.write( "Speed of boat without current = 15-9 = 6miles/hour
\n" ); document.write( "Speed of boat with current = 15+9=24miles/hour\r
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\n" ); document.write( "\n" ); document.write( "Check
\n" ); document.write( "======
\n" ); document.write( "120 miles in 20 hours upstream
\n" ); document.write( "time*speed= distance
\n" ); document.write( "time=distance/speed
\n" ); document.write( "time=120/6=20hours\r
\n" ); document.write( "\n" ); document.write( "120 miles in 5 hours downstream
\n" ); document.write( "time*speed= distance
\n" ); document.write( "time=distance/speed
\n" ); document.write( "time=120/24=5hours
\n" ); document.write( "
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