document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=850408>Question 850408</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The ratio of the number of stamps John had to the number of stamps Peter had was 4:1. after John bought 13 more to add to his collection and Peter was given 7 more by his brother, the ratio became 3:1. How many stamps did John and Peter have at first?\r<BR>\n" );
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document.write( "I try to solve the problem sum by using two changing quantities ratio method but cannot get the answer. Please let me know the reason and show me how to solve the sum. Thank you. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #512117 by </B><A HREF=/tutors/aboutme.mpl?userid=rothauserc><B>rothauserc(4718)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=rothauserc><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=rothauserc><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=512117\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> let the number of stamps Peter has be x and then John has 4x<BR>\n" );
document.write( "now John got 13 more stamps and Peter got 7, therefore<BR>\n" );
document.write( "(4x+13) / (x+7)  =  3/1<BR>\n" );
document.write( "now cross multiply the fractions<BR>\n" );
document.write( "4x+13 = 3*(x+7)<BR>\n" );
document.write( "4x+13 = 3x+21<BR>\n" );
document.write( "x = 8<BR>\n" );
document.write( "at first Peter had 8 stamps and John had 32 stamps<BR>\n" );
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