document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1205973>Question 1205973</A>: <I><SPAN STYLE=\"word-break: break-all;\"> It takes Leon 17 hours to seal his driveway working by himself. If Michael helps​ Leon, they can seal the driveway in 5 hours. How long would it take Michael to seal the driveway​ alone? </SPAN>\n" );
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document.write( "Let's say the driveway is 170 square feet in area.<BR>\n" );
document.write( "Feel free to pick any other positive real number. <BR>\n" );
document.write( "It turns out the driveway area doesn't affect the final answer.\r<BR>\n" );
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document.write( "If Leon takes 17 hours to do the job by himself, then his unit rate is 170/17 = 10 square feet per hour.<BR>\n" );
document.write( "The formula is: unit rate = (amount done)/time\r<BR>\n" );
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document.write( "Assuming neither worker hinders the other, the two men work together at a combined rate of 170/5 = 34 square feet per hour.\r<BR>\n" );
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document.write( "Michael's unit rate when working alone is 34-10 = 24 square feet per hour.<BR>\n" );
document.write( "This is because each person's unit rate combine together to get 34 square feet per hour.\r<BR>\n" );
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document.write( "So Michael will take 170/24 = 85/12 = 7 & 1/12 hours if he works alone.<BR>\n" );
document.write( "The formula here is:  time = (amount done)/(unit rate)\r<BR>\n" );
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document.write( "That mixed number 7 & 1/12 hours is a bit clunky in my opinion. <BR>\n" );
document.write( "Let's convert to hours+minutes format.<BR>\n" );
document.write( "1 hour = 60 min<BR>\n" );
document.write( "1/12 of an hour = 60*(1/12) = 5 minutes<BR>\n" );
document.write( "So 7 & 1/12 hour = <font color=red>7 hours + 5 minutes</font>\r<BR>\n" );
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document.write( "Or if you wanted purely minutes,<BR>\n" );
document.write( "1 hour = 60 min<BR>\n" );
document.write( "7 hours = 7*60 = 420 min<BR>\n" );
document.write( "7 hours + 5 min = 420 min + 5 min = 425 min<BR>\n" );
document.write( "Note that 425/60 = 85/12<BR>\n" );
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