document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1129384>Question 1129384</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The area of a circle is 3 1/7 times the square of the radius.  Find weight of a circular disc of cast iron 7 ft. in diameter and 1 1/3 in. thickness.  \r<BR>\n" );
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document.write( "A plate of cast iron 1 ft. square and 1 in. thickness weighs 37.5 lbs. \r<BR>\n" );
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document.write( "Attempt:\r<BR>\n" );
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document.write( "The disc is a cylinder.\r<BR>\n" );
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document.write( "Volume; pi * r*2 * height.  3.1416 * 3.5 * 3.5 * .1108333 = 4.265375 cu. ft.\r<BR>\n" );
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document.write( "Not sure how to continue.  </SPAN>\n" );
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document.write( "The solution by tutor @josgarithmetic is not correct; he misread the given information about the weight of cast iron.<br><BR>\n" );
document.write( "The given information is that a plate of cast iron 1 foot square and 1 inch thick weighs 37.5 pounds.  Although it is unorthodox to do calculations in mixed units (square feet times inches), it is possible to do so if you pay attention to what you are doing.<br><BR>\n" );
document.write( "The volume of the given cylindrical disk is<br><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28pi%29%28r%5E2%29%28h%29+=+%2822%2F7%29%283.5%5E2%29%284%2F3%29 ALIGN=MIDDLE  ALT=\"%28pi%29%28r%5E2%29%28h%29+=+%2822%2F7%29%283.5%5E2%29%284%2F3%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > in units of square feet times inches.<br><BR>\n" );
document.write( "Then, since the given information about the weight of cast iron is in those same  mixed units, the weight of the disk is<br><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%2822%2F7%29%283.5%5E2%29%284%2F3%29%2837.5%29+=+1925 ALIGN=MIDDLE  ALT=\"%2822%2F7%29%283.5%5E2%29%284%2F3%29%2837.5%29+=+1925\"   DISABLED_style= \"max-width:90%; height:auto;\" ><br><BR>\n" );
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