document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=285772>Question 285772</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Sparrows and pigeons sit on a fence. When 5 sparrows leave, there remain 2pigeons for every sparrow. Then 25 pigeons leave and the ratio of sparrows to pigeons becomes 3 : 1.What is the original number of birds?\r<BR>\n" );
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document.write( "A. 50 B. 48 C. 75 D. 30 E. None of these.<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 #207379 by </B><A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><B>ankor@dixie-net.com(22740)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><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=ankor@dixie-net.com><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=207379\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Sparrows and pigeons sit on a fence.<BR>\n" );
document.write( " When 5 sparrows leave, there remain 2pigeons for every sparrow.<BR>\n" );
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document.write( "What is the original number of birds?<BR>\n" );
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document.write( "\"When 5 sparrows leave, there remain 2pigeons for every sparrow.<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28s-5%29%2Fp ALIGN=MIDDLE  ALT=\"%28s-5%29%2Fp\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%2F2 ALIGN=MIDDLE  ALT=\"1%2F2\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Cross Multiply<BR>\n" );
document.write( "p = 2(s-5)<BR>\n" );
document.write( "p = 2s - 10<BR>\n" );
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document.write( "\"Then 25 pigeons leave and the ratio of sparrows to pigeons becomes 3 : 1.<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28s-5%29%2F%28p-25%29 ALIGN=MIDDLE  ALT=\"%28s-5%29%2F%28p-25%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=3%2F1 ALIGN=MIDDLE  ALT=\"3%2F1\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Cross multiply<BR>\n" );
document.write( "s-5 = 3(p-25)<BR>\n" );
document.write( "s - 5 = 3p - 75<BR>\n" );
document.write( "s = 3p - 75 + 5<BR>\n" );
document.write( "s = 3p - 70<BR>\n" );
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document.write( "Replace p with (2s-10) derived from the 1st ratio<BR>\n" );
document.write( "s = 3(2s-10) - 70<BR>\n" );
document.write( "s = 6s - 30 - 70<BR>\n" );
document.write( "s = 6s - 100<BR>\n" );
document.write( "100 = 6s - s<BR>\n" );
document.write( "s = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=100%2F5 ALIGN=MIDDLE  ALT=\"100%2F5\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "s = 20 sparrows<BR>\n" );
document.write( "then<BR>\n" );
document.write( "p = 2(20) - 10<BR>\n" );
document.write( "p = 30 pigeons<BR>\n" );
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document.write( "A total of 50 birds<BR>\n" );
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document.write( "You can check the solutions in the two ratio statements<BR>\n" );
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