document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1123070>Question 1123070</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A Telecommunication Company has two services – the tango and the contract. The contract has fixed charge of N$ 110 per month plus N$ 1.15 per minute of talking time. The Tango charge N$ 1.95 per minute.<BR>\n" );
document.write( "a) What are the total monthly charges for each service for talking time of 121 hours?<BR>\n" );
document.write( "b) After how many minutes of talking time will the two services cost the same?<BR>\n" );
document.write( "c) If you spend N$ 900 per month on tango cards, how much would you save having the contract service? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #739322 by </B><A HREF=/tutors/aboutme.mpl?userid=Theo><B>Theo(13342)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Theo><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=Theo><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=739322\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 121 hours * 60 minutes per hour = 7260 minutes.\r<BR>\n" );
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document.write( "contract would charge you 110 + 1.15 * 7260 = 8459 for the month.\r<BR>\n" );
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document.write( "tango card would charge you 1.95 * 7260 = 14157 for the month.\r<BR>\n" );
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document.write( "that seems like very heavy usage and a very high cost per month for talking on the phone.\r<BR>\n" );
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document.write( "if you meant 121 minutes, then.....\r<BR>\n" );
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document.write( "contract would charge you 110 + 1.15 * 121 = 249.15.\r<BR>\n" );
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document.write( "tango card would charge you 1.95 * 121 = 235.95\r<BR>\n" );
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document.write( "to determine how many minutes of talking time it would take for the contract to cost the same as the tango card, you would use the following formula.\r<BR>\n" );
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document.write( "110 + 1.15 * x = 1.95 * x\r<BR>\n" );
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document.write( "x represents the number of minutes of use for the month.\r<BR>\n" );
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document.write( "subtract 1.15 * x from both sides of this equation to get 110 = 1.95 * x - 1.15 * x<BR>\n" );
document.write( "combine like terms to get 110 = .80 * x<BR>\n" );
document.write( "divide both sides of this equation by .80 to get 110 / .80 = x<BR>\n" );
document.write( "solve for x to get x = 110 / .80 = 137.5\r<BR>\n" );
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document.write( "when the number of minutes of use is 137.5, the contract will cost the same as the tango card.\r<BR>\n" );
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document.write( "cost is 110 + 1.15 * 137.5 = 268.125 when using the contract.\r<BR>\n" );
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document.write( "cost is 1.95 * 137.5 = 268.125 when using the tango card.\r<BR>\n" );
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document.write( "when you spend 900 a month on the tango card, your number of minutes of use for the month would be at most 900 / 1.95 = 461.5384615.\r<BR>\n" );
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document.write( "for that same number of minutes, the contract would cost you 110 + 1.15 * 461.5384615 = 640.7692305.\r<BR>\n" );
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document.write( "you would save 900 - 640.7692305 = 259.2307692 per month by using the contract rather than the tango card.\r<BR>\n" );
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document.write( " </SPAN>\n" );
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