A2 Probability Review

Clare picks a marble at random, puts it back, and then picks another marble at random.

• Dependent
• Independent

You pick a marble from this bag.
What is the probability you will choose either a black or white marble?

• 3/5
• 9/100
• 1/10
• 2/5

The tree diagram shows the outcomes of rolling a die and flipping a coin.  
What is the probability of rolling a number higher than 3 and flipping a tails?

• ¹/₁₂
• ²/₁₂
• ³/₁₂
• ⁴/₁₂

P(B or E) = 
*Remember to simplify.*

• 1/2
• 1/4
• 1/8
• 4/8

Classify each pair of events as dependent or independent. 
Roll a number cube. Then toss a coin.

• Independent
• Dependent

Which formula do you use when two events are mutually exclusive?

• P(A or B) = P(A) + P(B)
• P(A or B) = P(A) + P(B) - P(both)
• P(A and B) = P(A) * P(B)
• P (A and B) = P(A) * P(B|A)

A die is rolled.  What is the probability of rolling a 5 or a number greater than 3?

• 2/3
• 1/2
• 5/6
• 1

A bag has 10 marbles. What is the probability of pulling a red?

• 3/10

• 3/9

• 1/9

• 1/3

A jar contains 2 pink, 6 red, and 4 blue marbles. If you pick one marble without looking, what is the probability that the marble you pick will be red or blue?

• 5/6
• 1/2
• 1/3
• 1/6

How many outfits are possible with 2 pairs of jeans, 5 t-shirts, and 2 pairs of shoes? (Hint: Use a list, tree diagram or the Fundamental Counting Principle.)

• 9

• 40

• 20

• 10