document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=363042>Question 363042</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A salesman sells a car to one out of 20 customers. What is the probability that he will sell two out of three cars? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #258770 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=258770\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> the probability that he will sell 1 car is (1/20) = .05\r<BR>\n" );
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document.write( "the probability that he will sell exactly 2 out of 3 cars is equal to:\r<BR>\n" );
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document.write( ".05 * .05 * .95 * the number of ways this can happen.\r<BR>\n" );
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document.write( "the number of ways this can happen is 3! / (2! * 1!) = 3\r<BR>\n" );
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document.write( "the general equation for that is n! / (x! * (n-x)!)\r<BR>\n" );
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document.write( "n is the total members of the set.<BR>\n" );
document.write( "x is the number of members of the set that you draw from.\r<BR>\n" );
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document.write( "n is equal to 3 which is the total number of cars that can be sold.<BR>\n" );
document.write( "x is equal to 2 which is the number of cars from the total number of cars that this salesmen will sell.\r<BR>\n" );
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document.write( "the probability is therefore equal to .05 * .05 * .95 * 3 = .007125\r<BR>\n" );
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document.write( "the 3 possible ways are:\r<BR>\n" );
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document.write( "he sells the 1st and 2d car but not the 3d.<BR>\n" );
document.write( "he sells the 1st and 3d car but not the 2d.<BR>\n" );
document.write( "he sells the 2d and 3d car but not the 1st.\r<BR>\n" );
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document.write( "since there are 3 possible ways and the probability for each way is the same, then the total probability is 3 * the probability for each way.\r<BR>\n" );
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document.write( "the probability for each way is .05 * .05 * .95 (first way) which is the same as .05 * .95 * .05 (second way) which is the same as .95 * .05 * .05 (third way).\r<BR>\n" );
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document.write( " </SPAN>\n" );
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