document.write( "Question 178779: Two cranes, operating together, can unload a cargo ship in 4 hours. If it takes one crane twice as long as the other to unload the ship, how long would it take each crane to unload the ship by itself? \n" ); document.write( "

Algebra.Com's Answer #133754 by solver91311(24713) $\"\"$ $\"About$

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\n" ); document.write( "\n" ); document.write( "Let x be the number of hours it takes thing A to do one job. Then thing A can do

of the job in 1 hour. If thing B takes twice as long, then 2x represents the number of hours it takes thing B to do the same job, and thing B can do

of the job in 1 hour.\r
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\n" ); document.write( "\n" ); document.write( "Together, thing A and thing B can do

of the job in 1 hour.\r
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\n" ); document.write( "\n" ); document.write( "That means that thing A and thing B can do the entire job in

hours.\r
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\n" ); document.write( "\n" ); document.write( "But we are given that thing A and B can do the entire job in 4 hours.\r
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\n" ); document.write( "\n" ); document.write( "Solve for x in

to get the time it takes A to do the job, and double it to get the time for thing B.\r
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\n" ); document.write( "\n" ); document.write( "Notice I described this as 'thing A' and 'thing B' and just called what they were doing a 'job' That's because this method works for 'painting a room' questions, 'two different sized pipes filling or emptying a tank' problems, and anything else like it.\r
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