Answer:
Step-by-step explanation:
The persons who have diseases = 19%
The persons who do not have diseases = 81%
Probability for the test showing positive = Prob of actual disease and shows positive + Prob of no disease but test shows wrong
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Prob that the person actually has the disease given that the test administered to an individual is positive= 
30) A B C total
2x 7x x 10x
P(A) = 0.2, P(B) = 0.7, P(C) = 0.1
Let D be the event that the product is defective
P(D/A) = 0.032, P(D/B) = 0.034 and P(D/C) = 0.056
Required probability =P(C/D)
= 
by using Bayes theorem for conditional probability
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32) 7 digit phone numbers with repitition including 0 will be
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Numbers which have atleast one 7 = total number - numbers which do not have a single 7
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the probability that a 7-digit phone number contains at least one 7
=