Probability Quest 7.8 and 8.11

Which pair of events is a dependent one?

• A student rolls a 3 on a number cube. A second student then rolls a 3 on the same number cube.

• There are 4 yellow cards and 6 blue cards in a box. A student randomly draws a yellow card then replaces it. A second student then randomly draws a blue card.

• There are 5 red erasers and 7 green erasers in a bag. A student randomly draws a red eraser and replaces it. A second student then randomly draws a green eraser.

• There are 7 gold tokens and 4 silver tokens in a cup. The first student randomly draws a gold token and keeps it. A second student randomly draws a gold token from the cup.

Which pair of events is a dependent one?

• A student tosses a coin and it lands on heads. A second student tosses the coin and it lands on tails.

• There are 5 dimes and 2 pennies in a cup. The first student randomly draws a dime and replaces it. The second student then randomly draws a penny.

• There are 5 red marbles and 6 blue marbles. One student randomly draws a blue marble and replaces it. The second student then randomly draws another blue marble.

• There are nine slips of paper in a bag numbered 1 through 9. The first student randomly draws a slip of paper and keeps it. The second student then randomly draws a slip of paper from the bag.

Which pair of events is a dependent one?

• rolling a 6 on a number cube and then rolling a 1 on the same number cube

• one girl born on July 29 and another girl born on July 29 the next year

• drawing a purple card from a deck of cards and then, without replacement, drawing another purple card

• drawing a red button out of a bag of red and white buttons, replacing the button, and then drawing out another red button

Taniesha has a bag containing 3 red marbles and 4 green marbles. She has another bag containing 2 yellow cubes and 5 orange cubes. She reaches into the second bag and selects an orange cube. These events are

• dependent because she uses 2 different shapes.

• dependent because she does not replace the marble.

• independent because she draws from 2 different bags.

• independent because she does not draw them both at the same time.

Which pair of events is independent?

• Francisco sits in the first desk, then Alejandro sits in the desk behind Francisco.

• Mrs. Quintana selects a student to answer a question, then she selects a problem out of the book.

• Daryl removes a fish from an aquarium, then he removes a second fish from the same aquarium.

• Olivia selects a marble from a bag and does not replace it, then she selects a second marble from the same bag.

In a classroom of 20 kids, 3 girls are named Stephanie and 2 boys are named John. The probability that a student picked at random is named John is ___out of ___.

• 0 out of 1

• 1 out of 3

• 1 out of 5

• 1 out of 10

• 5 out of 10

A bag contains marbles of four different colors:

8 blue marbles

24 red marbles

16 green marbles

4 yellow marbles

​The probability of picking a blue ball at random out of the bag is

• 1/8

• 2/13

• 1/4

• 8/11

• 1/2

• $\frac{1}{12}$

• $\frac{1}{4}$

• $\frac{3}{7}$

• $\frac{4}{9}$

• $\frac{1}{12}$

• $\frac{2}{12}$

• $\frac{4}{12}$

• $\frac{6}{12}$

A cup contains one red marble, one white marble, and one black marble. Juan randomly draws one black marble and replaces it. He repeats this process three more times and draws a black marble each time. What is the probability he will draw a black marble on his fifth attempt.

• $\frac{1}{5}$

• $\frac{1}{3}$

• $\frac{3}{5}$

• $\frac{2}{3}$