Question 323788
Of all the iPods in a large shipment, 2% have a defective battery, 
1% has a defective headphone jack, 
and 0.5% have both defects. 
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If you purchase one at random, find the probability it 
has each of the following:
a. A defective battery OR defective headphone jack.
= p(db)+P(hj) - P(db and hj) 
= 0.02 + 0.01 - 0.005 = 0.025
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b. A good battery AND good headphone jack.
= P((db)' and (hj)'] = P(db)' + P(hj)' - P((db)' OR (hj)
= 0.98 + 0.99 - 0.995 = 0.97.5
==========================================                           c. Exactly c. One of the two defects.

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Cheers,
Stan H.