Question 1-4

1. Three hundred adults over 5|] years of age were classied according to their smoking habits and their history of heart attacks. The results are shown in table below. a) What is the probability of selecting a person who has either no heart attack or who is a nonsmoker? b) Given that the selected person is a heavy smoker. what is the probability that he or she will have a heart attack? 2. Two machines produce the same type of product. The older machine produces 25% of the total output but ?% are defective. The new machine produces ?S% of the total output but 2% are defective. Find the probability that: a) A product selected at random is from the old machine and is defective. b) A product selected at random is defective. c) A selected pmduct is from the new machine if it is defective. 3. A student hostel comprises 30% Part 1 students, 20% Part 2 students, and 5t}% Part 3 students. 2%. 4% and 5% of the Part 1, 2 and 3 students respectively have their own transport. l[Zine student is selected at random. a) Draw a tree diagram for the above information. b) What is the probability that a Part 1 student is without transport? c) What is the probability that a student is without transport? d) Given that a student is without transport. what is the pmbability that he or she is a Part 2 student? 4. Tan dc Co sources ?5% of its vegetables from Samy and the rest from Zamri. It is found that usually 10% of vegetables from Samy and 30% of vegetables om Zamri is dry. a) Draw a tree diagram. b) What is the probability that a batch of vegetables in Tan dc Co. becomes dry? c) A customer complained to Tan 8:. Co. that he was given a dry bunch of vegetables. What is the pmbability that the supply came from Zamri