document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=552330>Question 552330</A>: <I><SPAN STYLE=\"word-break: break-all;\"> As a new residential area with 1000 domestic homes is going to be built,<BR>\n" );
document.write( "the number of required parking lots is calculated in the following way:<BR>\n" );
document.write( "We assume that there is no relation between the number of cars in<BR>\n" );
document.write( "different homes. Furthermore, we assume that a domestic home has no<BR>\n" );
document.write( "car with probability 0.2, one car with probability 0.7 and two cars with<BR>\n" );
document.write( "probability 0.1. The number of parking lots should be planned in such<BR>\n" );
document.write( "way that the probability that each car gets a parking lot is 0.99.\r<BR>\n" );
document.write( "\n" );
document.write( "How many parking lots should be built? (the answer isn't 891) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #360218 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=360218\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> As a new residential area with 1000 domestic homes is going to be built,<BR>\n" );
document.write( "the number of required parking lots is calculated in the following way:<BR>\n" );
document.write( "We assume that there is no relation between the number of cars in<BR>\n" );
document.write( "different homes. Furthermore, we assume that a domestic home has no<BR>\n" );
document.write( "car with probability 0.2, one car with probability 0.7 and two cars with<BR>\n" );
document.write( "probability 0.1. The number of parking lots should be planned in such<BR>\n" );
document.write( "way that the probability that each car gets a parking lot is 0.99. <BR>\n" );
document.write( "How many parking lots should be built? (the answer isn't 891)<BR>\n" );
document.write( "-----------<BR>\n" );
document.write( "Expected # of cars per household = 0*0.2+1*0.7+2*0.1 =  0.9<BR>\n" );
document.write( "----------<BR>\n" );
document.write( "Expected # of cars in the community == 0.9*1000 = 900<BR>\n" );
document.write( "------<BR>\n" );
document.write( "# of parking lots ??<BR>\n" );
document.write( "Solve:<BR>\n" );
document.write( "Let # of lots be \"x\".<BR>\n" );
document.write( "900/x = 0.99<BR>\n" );
document.write( "x = 900/0.99<BR>\n" );
document.write( "x = 909.0909<BR>\n" );
document.write( "Rounded down: x = 909<BR>\n" );
document.write( "============================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( "====================== </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );