document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=178104>Question 178104</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Please help me with the following question. I have been trying to figure it out, but am having some difficulty.\r<BR>\n" );
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document.write( "Is this statement true or false? For any two events, the probability that one or the other of the events occurs equals the sum of the two individual probabilities.\r<BR>\n" );
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document.write( "How do you go about figuring this out? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #133044 by </B><A HREF=/tutors/aboutme.mpl?userid=gonzo><B>gonzo(654)</B></A><img src=\"/images/stars/stars-11.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=gonzo><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=133044\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> suppose you have a box with 4 balls in it.<BR>\n" );
document.write( "there's a red ball, a green ball, a white ball, and a blue ball.<BR>\n" );
document.write( "the probability of getting a red ball is 1/4 since 1 out of the 4 balls will provide you with success.<BR>\n" );
document.write( "the probability of getting a blue ball is 1/4 since 1 out of the 4 balls will provide you with success.<BR>\n" );
document.write( "the probability of getting a red ball or a blue ball is 2/4 since 2 out of the 4 balls will now provide you with success.  it's either a red, or a blue.<BR>\n" );
document.write( "this is the same as p(red) + p(blue) = 1/4 + 1/4.<BR>\n" );
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document.write( "look at another example:<BR>\n" );
document.write( "suppose you had 3 red balls, 5 green balls, 7 white balls, and 15 blue balls.<BR>\n" );
document.write( "total universe is now 3 + 5 + 7 + 15 = 30<BR>\n" );
document.write( "p(red) = 3/30<BR>\n" );
document.write( "p(blue) = 15/30<BR>\n" );
document.write( "p(red or blue) = (3+15)/30 = 18/30<BR>\n" );
document.write( "why?<BR>\n" );
document.write( "if you want to get a red, you only have 3 to pick from.<BR>\n" );
document.write( "if you want to get a blue, you only have 15 to pick from.<BR>\n" );
document.write( "if you want to get a red or a blue, you have 18 to pick from.<BR>\n" );
document.write( "this is the sum of the red and the blue balls.<BR>\n" );
document.write( "that's why p(a or b) = p(a) + p(b)<BR>\n" );
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document.write( "now p(a or b) = (3 + 15)/30 = 3/30 + 15/30 which is the same as p(a) + p(b)<BR>\n" );
document.write( "---\r<BR>\n" );
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document.write( " </SPAN>\n" );
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