document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1204320>Question 1204320</A>: <I><SPAN STYLE=\"word-break: break-all;\"> There were 360 red and blue marbles in a bag at first. 25% of the number of red marbles and 40% of the number of blue marbles were added. In the end, there were 471 marbles in the bag altogether.<BR>\n" );
document.write( "How many blue marbles were in the bag at first? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #840487 by </B><A HREF=/tutors/aboutme.mpl?userid=math_tutor2020><B>math_tutor2020(3820)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=math_tutor2020><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=840487\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <font color=black size=3><BR>\n" );
document.write( "b = number of blue marbles at first<BR>\n" );
document.write( "360-b = number of red marbles at first<BR>\n" );
document.write( "b > 0 and b is an integer\r<BR>\n" );
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document.write( "40% of b = 0.40b = number of blue marbles added<BR>\n" );
document.write( "b+0.40b = 1.40b = total number of blue marbles after adding those extra\r<BR>\n" );
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document.write( "1.25(360-b) = total number of red marbles after extra reds are added in\r<BR>\n" );
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document.write( "1.40b + 1.25(360-b) = 471<BR>\n" );
document.write( "1.40b + 450-1.25b = 471<BR>\n" );
document.write( "0.15b + 450 = 471<BR>\n" );
document.write( "0.15b = 471 - 450<BR>\n" );
document.write( "0.15b = 21<BR>\n" );
document.write( "b = 21/0.15<BR>\n" );
document.write( "b = 140<BR>\n" );
document.write( "360-b = 360-140 = 220\r<BR>\n" );
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document.write( "At first there are 140 blue marbles and 220 red marbles.\r<BR>\n" );
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document.write( "Check:\r<BR>\n" );
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document.write( "25% of red = 0.25*220 = 55 extra red added<BR>\n" );
document.write( "40% of blue = 0.40*140 = 56 extra blue added\r<BR>\n" );
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document.write( "55+56 = 111 extra marbles added<BR>\n" );
document.write( "360+111 = 471 which confirms the answer is correct.\r<BR>\n" );
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document.write( "Answer: There are 140 blue marbles to start with.<BR>\n" );
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