document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=427705>Question 427705</A>: <I><SPAN STYLE=\"word-break: break-all;\"> M+B+K do a task in 1h 20min<BR>\n" );
document.write( "M needs twice as long as B,<BR>\n" );
document.write( "M needs 2 hrs longer than K\r<BR>\n" );
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document.write( "Please formula, we try to figure out  the solution ourselves, but don't even have a starting formula... Thank you<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #297439 by </B><A HREF=/tutors/aboutme.mpl?userid=jorel1380><B>jorel1380(3719)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=jorel1380><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=jorel1380><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=297439\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> If M + B + K can do a task in 1hr 20min then they take 1-1/3 hours to do one task, or they can do 3/4 task per hour.  Let's say M can do 1/M amount of the task per 1 hour, then B=1/2M or M/2.  Since M takes 2 hrs longer than K, K=M-2.\r<BR>\n" );
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document.write( "To set up our equation, we have:\r<BR>\n" );
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document.write( "1/M + 1/M/2 + 1/M-2= 3/4<BR>\n" );
document.write( "1/M + 2/M + 1/M-2= 3/4<BR>\n" );
document.write( "3/M + 1/M-2= 3/4\r<BR>\n" );
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document.write( "Multiplying through by 4(M)(M-2), we get:<BR>\n" );
document.write( "12M-24+4M = 3M^2-6M<BR>\n" );
document.write( "0 =3M^2-22M+24<BR>\n" );
document.write( "0 = (3M-4)(M-6)<BR>\n" );
document.write( "M =4/3 or 6<BR>\n" );
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