Independent or dependent? Does putting it back matter?

Grade 8 Math Worksheet - Building Confidence

NameDate

Circle the best answer, or write your answer on the line.

2 red, 5 blue. Ari's bag holds 3 red and 5 blue marbles. Ari draws a red marble without looking and keeps it out. What is the chance the next draw is red, in simplest form?
3 green, 2 yellow. Bo's bag holds 4 green and 2 yellow marbles. Bo draws a green marble without looking and keeps it out. What is the chance the next draw is green, in simplest form?
2 red, 3 white (the red one went back). Esme's bag holds 2 red and 3 white marbles. Esme draws a red marble without looking and puts it back. What is the chance the next draw is red, in simplest form?
1, 2, 4, 5, 6, 7, 8, 9, 10. Jun has cards numbered 1 to 10 in a bag. Jun draws the card 3 without looking and keeps it out. What is the chance the next card is even, in simplest form?
5.
Kira rolls a fair number cube, then rolls it again. Are the two rolls independent or dependent?
- Independent: the cube is the same for both rolls
- Dependent: the same cube is used twice
- Dependent: the second roll comes later than the first
6.
Luz draws a marble from a bag without looking, keeps it out, then draws again. Are the two draws independent or dependent?
- Independent: both draws are done the same way, so nothing changes
- Independent: marbles cannot remember what was drawn before them
- Dependent: the first marble is kept out, so the bag changes
7.
Milo draws a marble from a bag without looking, puts it back, then draws again. Are the two draws independent or dependent?
- Dependent: both draws come from the same bag, so they are linked
- Dependent: the second draw is harder
- Independent: the marble goes back, so the bag is the same
Pia's bag holds 5 red and 3 blue marbles. Pia draws a red marble without looking and keeps it out. What is the chance the next draw is red, in simplest form?
Ren's bag holds cards numbered 1 to 6. Ren draws the card 2 without looking and puts it back. What is the chance the next draw is even, in simplest form?
Zee's bag holds 2 red and 6 blue marbles. Zee draws a red marble without looking and keeps it out. What is the chance the next draw is red, in simplest form?

Independent or dependent? Does putting it back matter?

Answer Key - Grade 8 Math Worksheet - Building Confidence

Circle the best answer, or write your answer on the line.

2 red, 5 blue. Ari's bag holds 3 red and 5 blue marbles. Ari draws a red marble without looking and keeps it out. What is the chance the next draw is red, in simplest form?
2/7
3 green, 2 yellow. Bo's bag holds 4 green and 2 yellow marbles. Bo draws a green marble without looking and keeps it out. What is the chance the next draw is green, in simplest form?
3/5
2 red, 3 white (the red one went back). Esme's bag holds 2 red and 3 white marbles. Esme draws a red marble without looking and puts it back. What is the chance the next draw is red, in simplest form?
2/5
1, 2, 4, 5, 6, 7, 8, 9, 10. Jun has cards numbered 1 to 10 in a bag. Jun draws the card 3 without looking and keeps it out. What is the chance the next card is even, in simplest form?
5/9
5.
Kira rolls a fair number cube, then rolls it again. Are the two rolls independent or dependent?
- Independent: the cube is the same for both rolls
- Dependent: the same cube is used twice
- Dependent: the second roll comes later than the first
6.
Luz draws a marble from a bag without looking, keeps it out, then draws again. Are the two draws independent or dependent?
- Independent: both draws are done the same way, so nothing changes
- Independent: marbles cannot remember what was drawn before them
- Dependent: the first marble is kept out, so the bag changes
7.
Milo draws a marble from a bag without looking, puts it back, then draws again. Are the two draws independent or dependent?
- Dependent: both draws come from the same bag, so they are linked
- Dependent: the second draw is harder
- Independent: the marble goes back, so the bag is the same
Pia's bag holds 5 red and 3 blue marbles. Pia draws a red marble without looking and keeps it out. What is the chance the next draw is red, in simplest form?
4/7
Ren's bag holds cards numbered 1 to 6. Ren draws the card 2 without looking and puts it back. What is the chance the next draw is even, in simplest form?
1/2
Zee's bag holds 2 red and 6 blue marbles. Zee draws a red marble without looking and keeps it out. What is the chance the next draw is red, in simplest form?
1/7