document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=916155>Question 916155</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 1. The average mass of some children in a group was 36kg. When one child who weighed 54kg left the group, the average mass of the remaining children decreased by 2kg. How many children were there in the group at first?<BR>\n" );
document.write( "Teacher's working: <BR>\n" );
document.write( "54kg-36kg=24kg<BR>\n" );
document.write( "18kg divided by 2= 9kg\r<BR>\n" );
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document.write( "2. A group of pupils calculated their average score for a science test. They noted that if anyone scored 14 marks more, their average score would be 90. If anyone scored 4 marks fewer, their average score would be 88. How many pupils are there in the group? <BR>\n" );
document.write( "Teacher's working:<BR>\n" );
document.write( "14+4=18<BR>\n" );
document.write( "18 divided by 2 =9\r<BR>\n" );
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document.write( "I don't understand why in the first question we minus and the second question plus. Can you explain both the questions? Please answer by today because tomorrow is my maths exam!!! Make the solution easy cause I'm still in P5!!<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 #555962 by </B><A HREF=/tutors/aboutme.mpl?userid=ewatrrr><B>ewatrrr(24785)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ewatrrr><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=ewatrrr><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=555962\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 1. 36n the total weight of group originally (concept of average weight)<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%2836n+-+54%29%2F%28n-1%29 ALIGN=MIDDLE  ALT=\"%2836n+-+54%29%2F%28n-1%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > = 34   (one weighing 54kg left group) <BR>\n" );
document.write( "36n - 54 = 34n - 34<BR>\n" );
document.write( "2n = 20<BR>\n" );
document.write( "n = 10 children were there in the group at first. Then 9 when one left.<BR>\n" );
document.write( "......<BR>\n" );
document.write( "2. T being the total of all scores originally<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28T+%2B+14%29%2Fn+=+90 ALIGN=MIDDLE  ALT=\"%28T+%2B+14%29%2Fn+=+90\"   DISABLED_style= \"max-width:90%; height:auto;\" > concept of Average score  <BR>\n" );
document.write( "T + 14 = 90n<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28T+-4%29%2Fn+=+88 ALIGN=MIDDLE  ALT=\"%28T+-4%29%2Fn+=+88\"   DISABLED_style= \"max-width:90%; height:auto;\" > concept of Average score<BR>\n" );
document.write( "T - 4 = 88n<BR>\n" );
document.write( "Finding n...<BR>\n" );
document.write( "T+14 = 90n<BR>\n" );
document.write( "<u>-(T-4 = 88n)</u><BR>\n" );
document.write( "18 = 2n<BR>\n" );
document.write( "9 = n </SPAN>\n" );
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