document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=169882>Question 169882</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A box contains 74 brass washer, 86 steel washers and 40 aluminium washers. Three washers are drawn at random from the box without replacement.\r<BR>\n" );
document.write( "\n" );
document.write( "a) Determine the probability that all three are steel washers.\r<BR>\n" );
document.write( "\n" );
document.write( "b) Determine the probability that there are no aluminium washers drawn, when three washers are drawn at random from the box without replacement.\r<BR>\n" );
document.write( "\n" );
document.write( "c) Find the probability that there are two brass washers and either a steel or an aluminium washer when three are drawn at random, without replacement. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #125311 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=125311\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A box contains 74 brass washer, 86 steel washers and 40 aluminium washers. Three washers are drawn at random from the box without replacement. <BR>\n" );
document.write( "a) Determine the probability that all three are steel washers.<BR>\n" );
document.write( "# of ways to succeed = 86C3<BR>\n" );
document.write( "# of possible outcomes = 200C3<BR>\n" );
document.write( "P(success) = 86C3/200C3 = 0.0779...<BR>\n" );
document.write( "------------------------------------------------- <BR>\n" );
document.write( "b) Determine the probability that there are no aluminium washers drawn, when three washers are drawn at random from the box without replacement.<BR>\n" );
document.write( "# of ways to succed = 114C3/200C2<BR>\n" );
document.write( "-------------------------------------------------- <BR>\n" );
document.write( "c) Find the probability that there are two brass washers and either a steel or an aluminium washer when three are drawn at random, without replacement.<BR>\n" );
document.write( "# of ways to succeed: <BR>\n" );
document.write( "Draw to brass washers in 74C2 ways<BR>\n" );
document.write( "Draw a steel or aluminum washer 126 ways<BR>\n" );
document.write( "Total # of ways to succeed 74C2*126 <BR>\n" );
document.write( "Prob of success: [74C2*126]/[200C3] = 0.25912<BR>\n" );
document.write( "=========================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );