document.write( "Question 661013: A box of ten items contains 7 good and 3 defective items. If a sample of two items is selected, what is the probability that:
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\n" ); document.write( "c. At least one will be good?\r
\n" ); document.write( "\n" ); document.write( "I don't know where to start. Please help me. Thank you! :) \n" ); document.write( "

Algebra.Com's Answer #411451 by Edwin McCravy(20060) $\"\"$ $\"About$

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A box of ten items contains 7 good and 3 defective items.
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document.write( "The box contains these items:\r\n" );
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document.write( "{G1,G2,G3,G4,G5,G6,G7,D1,D2,D3}, where the G's are good and the D's are defective.  \r\n" );
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document.write( "----------------------------------------\r\n" );
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\n" ); document.write( "If a sample of two items is selected, what is the probability that:
\n" ); document.write( "a. Both will be good?
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document.write( "That's when you choose 2 OUT OF these 7 {G1,G2,G3,G4,G5,G6,G7}\r\n" );
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document.write( "In probability, \"OUT OF\" means \"over\", so 2 out of 7 means \"2 over 7\",\r\n" );
document.write( "and that is .\r\n" );
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\n" ); document.write( "b. Both will be defective?
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document.write( "That's when you choose 2 OUT OF these 3 {D1,D2,D3}\r\n" );
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document.write( "In probability, \"OUT OF\" means \"over\", so 2 out of 3 means \"2 over 3\",\r\n" );
document.write( "and that is .\r\n" );
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\n" ); document.write( "c. At least one will be good?
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document.write( "Whenever you see \"AT LEAST ONE\" that means \r\n" );
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document.write( "1.  Find the probability of the COMPLEMENT event.\r\n" );
document.write( "2.  Subtract that probability from 1.\r\n" );
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document.write( "1. The COMPLEMENT event is when the EVENT FAILS.\r\n" );
document.write( "We will FAIL to get at least one good one if we get 2 defective ones.\r\n" );
document.write( "Therefore the complement event is the event we calculated the probability\r\n" );
document.write( "for in problem b. above. which we got to be   \r\n" );
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document.write( "2. 1 -  = \r\n" );
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document.write( "Edwin

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