Bluebook SAT Test Probability and Conditional Probability 9

Question 1

A box holds 9 cards numbered 1–9. A card is drawn at random. What is the probability the number is a perfect square?

Accepted Answer

1/3

Answer

1/9

Answer

2/9

Answer

4/9

Question 2

The two-way table below shows 200 employees categorized by department and remote-work status.

Remote   In-Office
Engineering   40       60
Marketing     30       70

If one employee is chosen at random, what is the probability they are in Engineering and work remotely?

Accepted Answer

1/5

Answer

2/5

Answer

3/10

Answer

2/7

Question 3

A bag contains 3 white balls and 7 black balls. Two balls are drawn without replacement. What is the probability both are black?

Accepted Answer

7/15

Answer

42/90

Answer

21/45

Answer

7/13

Question 4

In a survey of 400 people, 160 prefer tea, 200 prefer coffee, and 40 prefer neither. What is the probability that a randomly selected person prefers tea, given they have a preference (i.e., they don't prefer neither)?

Accepted Answer

2/5

Answer

1/3

Answer

4/9

Answer

8/18

Question 5

Events X and Y are independent. P(X) = 0.5 and P(Y) = 0.6. What is P(X and Y)?

Accepted Answer

0.30

Answer

0.10

Answer

0.25

Answer

0.55

Question 6

A class has 12 students: 5 freshmen, 4 sophomores, and 3 juniors. One student is selected at random. What is the probability the student is NOT a junior?

Accepted Answer

3/4

Answer

1/4

Answer

2/3

Answer

5/12

Question 7

A two-way table records 500 patients by treatment type and recovery outcome.

Recovered   Did Not Recover
Treatment A     150            50
Treatment B     200           100

If a recovered patient is selected at random, what is the probability they received Treatment A?

Accepted Answer

3/7

Answer

3/10

Answer

1/3

Answer

15/35