document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=205374>Question 205374</A>: <I><SPAN STYLE=\"word-break: break-all;\"> To use telephone banking to paybills,the customerhas to enter the last three digits of each bill. The numbers 0 to 9 inclusive can be used. If the numbers happen to be the same on more then one bill, the costumer has to enter the first 3 digits as well. <BR>\n" );
document.write( "A.) What is the probability that a person has 2 bills to register with the same last 3 digits?<BR>\n" );
document.write( "B.)What is the probability that a person with 10 bills to register has at least 2 bills with the same last 3 digits? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #155025 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=155025\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> If the numbers happen to be the same on more then one bill, the costumer has to enter the first 3 digits as well. <BR>\n" );
document.write( "A.) What is the probability that a person has 2 bills to register with the same last 3 digits?<BR>\n" );
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document.write( "P(a single digit from one bill is the same as a single digit from the other)<BR>\n" );
document.write( "= (1/10)<BR>\n" );
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document.write( "P(last thee from one are the same) = (1/10)^3 = 1/1000<BR>\n" );
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document.write( "B.)What is the probability that a person with 10 bills to register has at least 2 bills with the same last 3 digits?<BR>\n" );
document.write( "P(at least 2 of 10) = 1 - P(0<=x<=1) = 1 - binomcdf(10,1/10,1) = 0.2639<BR>\n" );
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document.write( "I used a TI calculator to find binomcdf(10,1/10,1)<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
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