document.write( "Question 1200474: a company produce parts, a quality control worker picks 12 parts and rates them. two of them were defective, and 10 were fine. what is the probability that he randomly picks two defective parts in a row? find the probability that at least one part is fine. find the probability that both parts are fine. \n" ); document.write( "

Algebra.Com's Answer #834621 by ikleyn(52781) $\"\"$ $\"About$

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\n" ); document.write( "a company $\"highlight%28cross%28produce%29%29\"$ produces parts, a quality control worker picks 12 parts and rates them.
\n" ); document.write( "two of them were defective, and 10 were fine.
\n" ); document.write( "(a) what is the probability that he randomly picks two defective parts in a row?
\n" ); document.write( "(b) find the probability that at least one part is fine.
\n" ); document.write( "(c) find the probability that both parts are fine.
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document.write( "The number of all possible pairs of 12 parts is   =  = 6*11 = 66.\r\n" );
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document.write( "(a)  Of these 66 different pairs, there is ONLY ONE PAIR consisting of two\r\n" );
document.write( "     defective parts.\r\n" );
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document.write( "     THEREFORE, the probability to pick two defective parts at a time is  .    ANSWER\r\n" );
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document.write( "(b)  Again, there are 66 different pairs, in total, and only one pair\r\n" );
document.write( "     contains two (both) defective parts.\r\n" );
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document.write( "     The rest, 66-1 = 65 pairs have AT LEAST one good part.\r\n" );
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document.write( "     THEREFORE, the probability to have at least one good part in a pair is  .    ANSWER\r\n" );
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document.write( "(c)  The number of pairs, having both good parts, is   =  = 5*9 = 45.\r\n" );
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document.write( "     THEREFORE, the probability that both parts are fine is   = .    ANSWER\r\n" );
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