document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1102605>Question 1102605</A>: <I><SPAN STYLE=\"word-break: break-all;\"> In an examination, a pupil's average marks were 63 per paper. If he had obtained 20 more marks for his Geography paper and 2 more marks for his History paper, his average per paper would have been 65. How many papers were there in the examination </SPAN>\n" );
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document.write( "If an additional 22 marks raised the average per paper by 2, then the number of papers was 22/2=11.<br><BR>\n" );
document.write( "You don't need to do any calculations with the actual marks to find that answer.  But if you want to, it might look like this:<br><BR>\n" );
document.write( "let x be the number of papers<br><BR>\n" );
document.write( "Then since the average mark was 63, the total number of marks was 63x<br><BR>\n" );
document.write( "Now you are changing the total number of marks to 63x+20+2 = 63x+22.<br><BR>\n" );
document.write( "The new average is 65:<br><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%2863x%2B22%29%2Fx+=+65 ALIGN=MIDDLE  ALT=\"%2863x%2B22%29%2Fx+=+65\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=63%2B22%2Fx+=+65 ALIGN=MIDDLE  ALT=\"63%2B22%2Fx+=+65\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=22%2Fx+=+2 ALIGN=MIDDLE  ALT=\"22%2Fx+=+2\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+11 ALIGN=MIDDLE  ALT=\"x+=+11\"   DISABLED_style= \"max-width:90%; height:auto;\" > </SPAN>\n" );
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