document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=411911>Question 411911</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A group of co-workers agreed that each would contribute the same amount to buy their boss a $100 birthday gift. At the last minute, 2 of the people decided not to chip in. This increased the amount that the remaining had to contribute by $2.50 per person. How many people actually contributed to the gift?\r<BR>\n" );
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document.write( "y=(x-2)+2.50(100)<BR>\n" );
document.write( "y=x-2+250<BR>\n" );
document.write( "y=x+248<BR>\n" );
document.write( "y-248=x<BR>\n" );
document.write( "y=(y-248-2)+250<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #289446 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=289446\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A group of co-workers agreed that each would contribute the same amount to buy their boss a $100 birthday gift. At the last minute, 2 of the people decided not to chip in. This increased the amount that the remaining had to contribute by $2.50 per person. How many people actually contributed to the gift? <BR>\n" );
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document.write( "Let original # of contributers be \"x\".<BR>\n" );
document.write( "Original aver cost per person is 100/x<BR>\n" );
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document.write( "After 2 dropped out the # is \"x-2\"<BR>\n" );
document.write( "New aver cost is 100/(x-2)<BR>\n" );
document.write( "----<BR>\n" );
document.write( "Equation:<BR>\n" );
document.write( "New aver - Old aver = 2.50<BR>\n" );
document.write( "100/(x-2) - (100)/x = 2.50<BR>\n" );
document.write( "------<BR>\n" );
document.write( "100x -100(x-2) = 2.5x(x-2)<BR>\n" );
document.write( "200 = 2.5x^2-5x<BR>\n" );
document.write( "2.5x^2-5x-200 = 0<BR>\n" );
document.write( "25x^2-50x-2000 = 0<BR>\n" );
document.write( "x^2 - 2x- 80 = 0<BR>\n" );
document.write( "(x-10)(x+8) = 0<BR>\n" );
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document.write( "Positive solution:<BR>\n" );
document.write( "x = 10 (original number of co-workers)<BR>\n" );
document.write( "x-2 = 8 (# of workers who contributed to the present)<BR>\n" );
document.write( "===================================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( "========= </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );