1. When does the union of two events occur?

A. Both event A and event B occur

B. Either event A or event B occurs

C. Event A and event B are mutually exclusive

D. Neither event A and event B occur

2. What do you call the collection of all outcomes that is an element of one or the other of the

sets A and B, or both of them?

A. Complement B. Condition C. Intersection D. Union

3. In the formula for finding the probability of a union of two events:

P( A U B) = P(A) + P(B) - P(A B), why is P(A B) subtracted from

P(A) + P(B)?

A. P(A B) has been counted twice through P(A) and P(B).

B. There is no explanation other than it's just a part of the rule.

C. This rule determines the probability of event A or B occurring, not A and B, so this factor is subtracted.

D. Either A or C

4. From a deck of 52 cards, what is the probability of drawing a number card or a spade?

A. 10 13

B. 49 52

C. 40

D. 49

5. Two dice are tossed at the same time, what is the probability of getting a sum greater

than 10?

A. 1 3

B. 1 13

C. 1 12

D. 3

6. Fifteen balls in a jar are numbered from 1 to 15. A ball is drawn at random. What is the

probability that the number on the ball is less than 6 or even.

A. 2 15

B. 5 15

C. 7 15

D. 2 3

7. What is P(AB) if P(A) = 0.65, P(B) = 0.30 and P(AB) = 0.75?

A. 0.65 B. 0.30 C. 0.20 D. 0.15

8. Mang Pepito has a farm with chickens and pigs. 27% are chickens and 39% are pigs. What

is the probability that an animal chosen in random is either a chicken or a pig?

A. 0.73 B. 0.66 C. 0.39 D. 0.12

9. In a class of 29 students, 15 like Science and 21 like Math. They all like at least 1 of the

two subjects. What is the probability that a student chosen in random likes Math or

Science?

A. 7 29

B. 14 29

C. 15 29

D. 1