L33 · Compound events

1. 1.

   A bag has 4 green marbles out of 8. Two marbles are drawn without replacement. P(both green)?

   Answer. 314

   48 × 37 = 314.

2. 2.

   A bag has 3 green marbles out of 7. Two marbles are drawn with replacement. P(both green)?

   Answer. 949

   37 × 37 = 949.

3. 3.

   A bag has 2 green marbles out of 6. Two marbles are drawn without replacement. P(both green)?

   Answer. 115

   26 × 15 = 115.

4. 4.

   A bag has 2 green marbles out of 4. Two marbles are drawn without replacement. P(both green)?

   Answer. 16

   24 × 13 = 16.

5. 5.

   A bag has 5 green marbles out of 9. Two marbles are drawn without replacement. P(both green)? Then Ava needs 5 of that amount. What is the total they need?

   Answer. 1718

   59 × 48 = 518. Then multiply by 5: 1718.

6. 6.

   A bag has 5 green marbles out of 8. Two marbles are drawn with replacement. P(both green)? Then Malik needs 3 of that amount. What is the total they need?

   Answer. 11164

   58 × 58 = 2564. Then multiply by 3: 11164.

7. 7.

   A bag has 3 green marbles out of 7. Two marbles are drawn without replacement. P(both green)? Then Elena needs 4 of that amount. What is the total they need?

   Answer. 47

   37 × 26 = 17. Then multiply by 4: 47.

8. 8.

   A bag has 5 green marbles out of 7. Two marbles are drawn with replacement. P(both green)? Then Nora needs 3 of that amount. What is the total they need?

   Answer. 12649

   57 × 57 = 2549. Then multiply by 3: 12649.

9. 9.

   A bag has 2 green marbles out of 7. Two marbles are drawn without replacement. P(both green)? Then Grace needs 3 of that amount. What is the total they need?

   Answer. 17

   27 × 16 = 121. Then multiply by 3: 17.

10. 10.

    A bag has 2 green marbles out of 7. Two marbles are drawn without replacement. P(both green)? Then Mei needs 3 of that amount. What is the total they need?

    Answer. 17

    27 × 16 = 121. Then multiply by 3: 17.

11. 11.

    Think

    Priya tried this problem:
    A bag has 2 green marbles out of 5. Two marbles are drawn with replacement. P(both green)?
    Priya wrote 426. That is not correct. What is the right answer?

    Answer. 425

    Priya’s answer 426 is off. 25 × 25 = 425.

12. 12.

    Think

    Jonah tried this problem:
    A bag has 2 green marbles out of 6. Two marbles are drawn without replacement. P(both green)?
    Jonah wrote 116. That is not correct. What is the right answer?

    Answer. 115

    Jonah’s answer 116 is off. 26 × 15 = 115.

Original extra practice. Keys are computed from the items, not guessed.