Independent or dependent? Does putting it back matter?

Grade 8 Math Worksheet

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

  1. Bo spins a spinner with 4 equal parts (red, blue, yellow, green) twice. Are the two spins independent or dependent?

    • Independent: the spinner is the same for both spins
    • Dependent: the arrow is less likely to stop on the same color twice
    • Dependent: the same spinner is used twice
  2. Esme deals two cards, without looking, from a pile of 10 number cards. The first card is not put back. Are the two cards independent or dependent?

    • Independent: cards have numbers, not colors, so the pile cannot change
    • Independent: the pile was shuffled first
    • Dependent: the first card is not put back, so the pile changes
  3. Jun's teacher picks two class helpers by drawing names from a hat of 25, without looking. The first name stays out. Independent or dependent?

    • Independent: there are many names
    • Independent: each name is drawn without looking
    • Dependent: the first name stays out, so the hat changes
  4. Kira's bag holds 7 red and 5 blue marbles. Kira draws a blue marble without looking and keeps it out. What is the chance the next draw is blue, in simplest form?

  5. Milo has cards numbered 1 to 20 in a bag. Milo draws the card 8 without looking and keeps it out. What is the chance the next card is odd, in simplest form?

  6. Tala's bag has 3 red and 5 blue marbles. The first draw, without looking, is red. Is a red second draw more likely if the first is put back, or kept out?

    • Kept out: 2/7 is more than 3/8
    • Put back: 3/8 is more than 2/7
    • The same: the bag started the same both ways
  7. Zee's bag has 3 red and 5 blue marbles. The first draw, without looking, is red. Is a blue second draw more likely if the first is put back, or kept out?

    • The same: the blue marbles were not touched
    • Put back: 5/8 is more than 5/7
    • Kept out: 5/7 is more than 5/8
  8. Ari's bag has 2 green and 4 white marbles. The first draw, without looking, is green. Is a green second draw more likely if the first is put back, or kept out?

    • Kept out: 1/5 is more than 1/3
    • Put back: 1/3 is more than 1/5
    • The same: the bag started the same both ways
  9. Pia's bag holds 4 red and 6 blue marbles. Pia draws a red marble without looking and puts it back. What is the chance the next draw is blue, in simplest form?

  10. Ren's bag holds 3 yellow and 7 green marbles. Ren draws a green marble without looking and keeps it out. What is the chance the next draw is green, in simplest form?

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Independent or dependent? Does putting it back matter?

Answer Key - Grade 8 Math Worksheet

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

  1. Bo spins a spinner with 4 equal parts (red, blue, yellow, green) twice. Are the two spins independent or dependent?

    • Independent: the spinner is the same for both spins
    • Dependent: the arrow is less likely to stop on the same color twice
    • Dependent: the same spinner is used twice
  2. Esme deals two cards, without looking, from a pile of 10 number cards. The first card is not put back. Are the two cards independent or dependent?

    • Independent: cards have numbers, not colors, so the pile cannot change
    • Independent: the pile was shuffled first
    • Dependent: the first card is not put back, so the pile changes
  3. Jun's teacher picks two class helpers by drawing names from a hat of 25, without looking. The first name stays out. Independent or dependent?

    • Independent: there are many names
    • Independent: each name is drawn without looking
    • Dependent: the first name stays out, so the hat changes
  4. Kira's bag holds 7 red and 5 blue marbles. Kira draws a blue marble without looking and keeps it out. What is the chance the next draw is blue, in simplest form?

    4/11
  5. Milo has cards numbered 1 to 20 in a bag. Milo draws the card 8 without looking and keeps it out. What is the chance the next card is odd, in simplest form?

    10/19
  6. Tala's bag has 3 red and 5 blue marbles. The first draw, without looking, is red. Is a red second draw more likely if the first is put back, or kept out?

    • Kept out: 2/7 is more than 3/8
    • Put back: 3/8 is more than 2/7
    • The same: the bag started the same both ways
  7. Zee's bag has 3 red and 5 blue marbles. The first draw, without looking, is red. Is a blue second draw more likely if the first is put back, or kept out?

    • The same: the blue marbles were not touched
    • Put back: 5/8 is more than 5/7
    • Kept out: 5/7 is more than 5/8
  8. Ari's bag has 2 green and 4 white marbles. The first draw, without looking, is green. Is a green second draw more likely if the first is put back, or kept out?

    • Kept out: 1/5 is more than 1/3
    • Put back: 1/3 is more than 1/5
    • The same: the bag started the same both ways
  9. Pia's bag holds 4 red and 6 blue marbles. Pia draws a red marble without looking and puts it back. What is the chance the next draw is blue, in simplest form?

    3/5
  10. Ren's bag holds 3 yellow and 7 green marbles. Ren draws a green marble without looking and keeps it out. What is the chance the next draw is green, in simplest form?

    2/3