Probability and Statistics test (25%) Time allowed 1:15Hr
HAWASSA UNIVERSITY
Name___________________________________ ID.No.______________
Department __________________ Section________ Year___________
1. Define Equally Likely Outcomes (2 points)
2. What is the difference between subset and proper subset? (2 points)
3. What is the difference between permutation and combination of objects (2 points)
Workout Questions
1. Out of 5 male workers and 7 female workers of a factory, a task force consisting of 5 workers is
to be formed. What is the probability that the task force will consist of (2 point each)
(a) 3 male and 2 female workers?
(b) all male workers?
(c) at most 3 male workers?
2. A blood test was made on 50 students. Among these 12 of them have blood type A, 8 of them
have type B, 13 of them have type AB and the rest have blood type O. If a student is selected
randomly from these group; what will be the probability that the person will have blood type: (1
point each)
Probability and Statistics test (25%) Time allowed 1:15Hr
a. O b. A c. AB d. B e. A or B f. O and B
3 In a certain assembly plant, three machines, B1, B2, and B3, make 30%, 45%, and25%,
respectively, of the products. It is known from past experience that 2%, 3%, and 2% of
the products made by each machine, respectively, are defective. Now, suppose that a
finished product is randomly selected. What is the probability that it is defective? (4
points)
4. A random sample of 200 adults are classified below by sex and their level of education
attained. (each 1.5 points)
If a person is picked at random from this group, find the probability that
(a) the person is a male given that the person has a secondary education
(b) the person does not have a college education given that the person is a female.
