Bluebook SAT Test Probability and Conditional Probability 8

Question 1

A two-way table records 500 households by internet speed and streaming usage.

Streams Daily  Does Not Stream
High-speed internet         180              70
Low-speed internet           60             190

What is the probability a household streams daily?

Accepted Answer

12/25

Answer

18/50

Answer

3/5

Answer

9/25

Question 2

P(A) = 0.7. If A and B are independent and P(A and B) = 0.28, what is P(B)?

Accepted Answer

0.40

Answer

0.42

Answer

0.30

Answer

0.98

Question 3

Three cards labeled 1, 2, and 3 are shuffled. Two cards are drawn one at a time without replacement. What is the probability the sum of the two cards equals 4?

Accepted Answer

1/3

Answer

1/6

Answer

2/3

Answer

1/2

Question 4

A store's records show that 60% of customers buy clothing, 40% buy accessories, and 20% buy both. What is the probability a customer buys clothing but NOT accessories?

Accepted Answer

2/5

Answer

3/5

Answer

1/2

Answer

1/5

Question 5

The two-way table shows 360 athletes by sport and injury history.

Injured  No Injury
Contact         90        60
Non-contact     50       160

What is the probability a randomly selected athlete is in a contact sport, given they have no injury?

Accepted Answer

3/11

Answer

2/5

Answer

3/7

Answer

1/3

Question 6

A bucket holds 8 balls: 3 orange and 5 gray. Three balls are drawn one at a time with replacement. What is the probability all three are gray?

Accepted Answer

125/512

Answer

5/8

Answer

15/56

Answer

25/64

Question 7

In a school of 800 students, 480 play at least one sport. If a student is chosen at random, what is the probability the student plays NO sports?

Accepted Answer

2/5

Answer

3/5

Answer

1/5

Answer

4/5