Probability Quiz Study Guide

A drawer contains 30 socks: 10 white, 12 black, and 8 gray. Which of the following is NOT true?

• The probability of choosing a black sock is 2/5

• The probability of choosing a white or gray sock is 3/5

• The probability of not choosing a gray sock is 11/15

• The probability of choosing a white sock is 2/3

A survey asked students their favorite fruit. If one student is chosen at random, which of the following is true?

• Apple is twice as likely to be chosen as banana

• Mango is more likely to be chosen than apple

• Banana is the most likely to be chosen

• Apple is half as likely as mango to be chosen

Mr. Lopez writes the names of his five pets—Buddy, Luna, Max, Coco, and Bella—on slips of paper and puts them in a jar. What is the theoretical probability of selecting the name Luna?

• 1/4

• 1/5

• 2/5

• 1/2

Mr. Lopez randomly draws a name and puts it back. He does this 12 times. The results are in the table.

What is the experimental probability of drawing Max?

• 1/6

• 1/4

• 1/3

• 1/5

Two dice are rolled. What is the probability of getting a 3 on the first die and an even number on the second?

• 1/12

• 1/6

• 1/3

• 1/4

Mia has two bags of marbles. Bag A has 3 red, 4 blue, and 3 green marbles. Bag B has 5 red, 1 blue, and 2 green marbles. What is the probability that she selects a green marble from each bag?

• 3/10

• 3/20

• 3/10 × 1/2

• 3/10 × 1/4

Olivia has a jar with 5 orange, 4 purple, 6 pink, and 5 yellow jellybeans. She picks two jellybeans without replacement. What is the probability she picks a yellow then a pink jellybean?

• 5/20 × 6/19

• 1/4 × 1/3

• 5/19 × 6/20

• 6/20 × 5/19

A spinner has 6 equal sections labeled 1 through 6. It is spun three times. What is the probability it lands on a number greater than 4 each time?

• 1/3 × 1/3 × 1/3

• 1/2 × 1/2 × 1/2

• 1/6

• 1/9

A bin has the following markers: 6 red, 9 green, 5 black, and 10 blue. What is the probability of selecting a green or black marker?

• 14/30

• 9/20

• 1/2

• 5/15

Two coins—one gold and one silver—are flipped. Which tree diagram correctly shows all possible outcomes?

• Gold: H/T, Silver: H/T

• Gold: H, Silver: H/T

• Gold: T/H, Silver: H only

• Silver: H/T only