document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1125843>Question 1125843</A>: <I><SPAN STYLE=\"word-break: break-all;\"> In a collection of black, white and blue marbles, there are 25% more black marbles than white marbles, and there are 40% more blue marbles than black marbles. If C is the number of black marbles, what is the total number of marbles? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #742152 by </B><A HREF=/tutors/aboutme.mpl?userid=kasperk><B>kasperk(4)</B></A><img src=\"/images/stars/iconNewId_16x16.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=kasperk><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=742152\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> \"25% more\" really means 100% + 25% = 125%, so when they say \"25% more black marbles than white marbles,\" it means \"Black is 125% of White.\" \r<BR>\n" );
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document.write( "<br>Similarly, \"40% more blue marbles than black marbles\" means \"Blue is 140% of Black.\"\r<BR>\n" );
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document.write( "<br>The question asks to use C to represent the number of black marbles, but I am going to do something that flows better by starting with W for the number of White marbles rather than C for the number of black marbles.\r<BR>\n" );
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document.write( "<br>Let W = the number of White marbles<BR>\n" );
document.write( "Since \"Black is 125% of White,\" we say Black = 1.25W because 125% in decimal form is 1.25 and the word \"of\" in math means multiply.<BR>\n" );
document.write( "Since \"Blue is 140% of Black,\" Blue = 1.40·Black = 1.40·(1.25W) = 1.75W\r<BR>\n" );
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document.write( "<br>So we now have:<BR>\n" );
document.write( "W = number of White<BR>\n" );
document.write( "1.25W = number of Black<BR>\n" );
document.write( "1.75W = number of Blue\r<BR>\n" );
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document.write( "<br>But the question asks us to use C for the number of Black marbles. Therefore, equate the above number of Black, 1.25W, with C --> 1.25W = C --> W = 0.8C. Now we can substitute W = 0.8C into the above expressions in terms of W:\r<BR>\n" );
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document.write( "<br>W = 0.8C = number of White marbles<BR>\n" );
document.write( "1.25W = C = number of Black marbles<BR>\n" );
document.write( "1.75W = 1.75(.8C) = 1.4C = number of Blue marbles\r<BR>\n" );
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document.write( "<br>If we add up blue + black + white, we have 0.8C + C + 1.4C = 3.2C<BR>\n" );
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