document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=981752>Question 981752</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The radius and height of a rught circular cone are 21 n 28cm. From its base to a height of 14 cm the portion of the curved surface was painted golden and the upper portiob as silver. Find the total cost of painting the whole curved surface at the rate of Rs50 /cm^2 for the golden colour and at the rate of Rs 40/cm^2 fir the silver colour.  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #602772 by </B><A HREF=/tutors/aboutme.mpl?userid=mananth><B>mananth(16946)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=mananth><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=mananth><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=602772\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The radius and height of a rught circular cone are 21 n 28cm. From its base to a height of 14 cm the portion of the curved surface was painted golden and the upper portiob as silver. Find the total cost of painting the whole curved surface at the rate of Rs50 /cm^2 for the golden colour and at the rate of Rs 40/cm^2 fir the silver colour. \r<BR>\n" );
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document.write( "The radius circular cone is 21  <BR>\n" );
document.write( "and height of a  28cm.\r<BR>\n" );
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document.write( " From its base to a height of 14 cm <BR>\n" );
document.write( "The lower part is a frustum of a cone\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/display-illustration.mpl?tutor=mananth&illustration_name=cone_painting\">.\r<BR>\n" );
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document.write( "Triangle AME and ANC are similar ( A A test of similarity)\r<BR>\n" );
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document.write( "14/28 = r1/21\r<BR>\n" );
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document.write( "r1= 10.5<BR>\n" );
document.write( "By Pythagoras theorem AC^2 = AN^2 +NC^2<BR>\n" );
document.write( "=28^2 +21^2<BR>\n" );
document.write( "=1225<BR>\n" );
document.write( "AC=35\r<BR>\n" );
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document.write( "Again \r<BR>\n" );
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document.write( "AM/AN = AE/AC<BR>\n" );
document.write( "1/2 = AE/AC <BR>\n" );
document.write( "1/2 = AE/35\r<BR>\n" );
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document.write( "AE = 17.5\r<BR>\n" );
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document.write( "The bottom portion is a frustum of cone<BR>\n" );
document.write( "Curved surface area of frustum = pi*(r1+r2)*l=pi*(21+10.5)*17.5<BR>\n" );
document.write( "=1732.5 cm^2<BR>\n" );
document.write( "Multiply by cost Rs. 50/cm^2<BR>\n" );
document.write( "= Rs. 86625\r<BR>\n" );
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document.write( "the curved surface of upper portion= pi*r*l\r<BR>\n" );
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document.write( "pi*10.5 * 17.5<BR>\n" );
document.write( "= 577.26 cm^2\r<BR>\n" );
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document.write( "multiply by 40<BR>\n" );
document.write( "=Rs 23,090.70\r<BR>\n" );
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document.write( "Add up both costs\r<BR>\n" );
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