Probability Quiz
Questions: 16 · 10 minutes
1. A random variable can take values 0, 1, or 2. Their probabilities are 0.20, 0.50, and an unknown value. What must the probability of the value 2 be?
0.50
0.20
0.30
0.70
2. In a group of 20 students, 12 travel by bus. Of those 12 bus riders, 3 arrived late. If a bus rider is selected, what is the probability that the student arrived late?
1/4
3/20
9/20
3/5
3. Two fair six-sided dice are rolled. What is the probability that their sum is 7?
1/6
1/12
7/36
1/3
4. A fair die is rolled twice. What is the probability of getting at least one 6?
1/6
11/36
1/36
1/3
5. A bag contains 3 red counters and 2 blue counters. Two counters are drawn without replacement. What is the probability that both are red?
6/25
3/10
2/5
3/5
6. A fair six-sided die is rolled once. What is the probability of rolling an even number?
1/3
5/6
2/3
1/2
7. A fair coin has landed on heads five times in a row. What is the probability that the next toss lands on tails?
1/6
1/2
1/4
5/6
8. The odds in favor of an event are 3 to 2. What is the probability that the event occurs?
2/5
1/2
2/3
3/5
9. Events A and B are independent, with P(A) = 0.60 and P(B) = 0.50. What is the probability that both occur?
0.10
0.25
0.30
0.55
10. A game gives you a 1/4 chance to win $12 and a 3/4 chance to lose $2. What is the expected monetary result per play?
A loss of $0.50
A gain of $1.50
A gain of $0.50
A gain of $3.00
11. Two fair coins are tossed. What is the probability of getting exactly one head?
1/4
1/3
3/4
1/2
12. A factory process produces a defective part with probability 0.02. Over 200 parts, how many defective parts would be expected on average?
0.04
2
4
20
13. A delivery has an 18% probability of being delayed. Assuming it must be either delayed or not delayed, what is the probability that it is not delayed?
18%
36%
72%
82%
14. A bag contains 4 green tokens and 6 other tokens. A token is drawn, replaced, and then another is drawn. What is the probability that both tokens are green?
0.16
0.24
0.36
0.40
15. Events A and B are mutually exclusive. If P(A) = 0.40 and P(B) = 0.35, what is P(A or B)?
0.75
0.14
0.40
1.00
16. For two events with nonzero probabilities, P(A given B) equals P(A). What relationship does this equality indicate?
A and B are mutually exclusive
A and B are equally likely
A and B are independent
A and B are complementary