500bottles contains 10 bottles that are defective.3bottles are selected,random,without replacement.a)what is the probability that the third one selected is defective given that the first was okay and second one selected was defective?b)what is the probability that the first one selected was defective and the second one selected was okay? c)what is the ptobability that exactly 1 defective bottle is selected?

Answer 1

there are 490 perfect bottles
a- (490/500)*(10/499)*(9/498)

b-(10/500)*(490/499)*(9/498)

c-(10/500*490/499*489/498)+(490/500*10/499*489/498)+(490/500*10/499*489/498)