document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1134960>Question 1134960</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A jar contains 3 pennies, 3 nickels and 2 dimes. A child selects 2 coins at random without replacement from the jar. Let X represent the amount in cents of the selected coins.\r<BR>\n" );
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document.write( "A) Find the probability X = 10. <BR>\n" );
document.write( "B) Find the probability X = 11. <BR>\n" );
document.write( "C) Find the expected value of X </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #752475 by </B><A HREF=/tutors/aboutme.mpl?userid=Boreal><B>Boreal(15235)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Boreal><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=Boreal><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=752475\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> X=10 means 2 nickels<BR>\n" );
document.write( "This has probability 3/8*2/7=3/28<BR>\n" );
document.write( "X=11 means a dime and a penny<BR>\n" );
document.write( "This has probability 2*(3/8*2/7), which is the same as 3/8*2/7+(2/8*3/7)=12/56 or 3/14 or 6/28<BR>\n" );
document.write( "The other possibilities include:<BR>\n" );
document.write( "X=2 (probability is 3/28)<BR>\n" );
document.write( "X=6 (probability is 2*3/8*3/7=18/56 or 9/28)<BR>\n" );
document.write( "X=15 (probability is 2*3/8*2/7 or 6/28)<BR>\n" );
document.write( "X=20 (probability is 2/8*1/7=1/28 \r<BR>\n" );
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document.write( "The probabilities add to 1<BR>\n" );
document.write( "E(X)=x*p*(X)<BR>\n" );
document.write( "=6/28+54/28+90/28+20/28+30/28+66/28<BR>\n" );
document.write( "=266/28<BR>\n" );
document.write( "=9.5 </SPAN>\n" );
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