Use a simulation to estimate a compound chance

Answer Key - Grade 8 Math Worksheet - Challenge Me

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

1. 1.

   Bo makes 70% of free throws. In 20 copied tries of 2 shots, 11 had both makes. How many percentage points is the estimate from the exact chance?

   6
2. 2.

   Esme's bus is late 20% of days, and it rains 40%. In 25 copied days, 3 had a late bus and rain. How many percentage points is the estimate from the exact chance?

   4
3. 3.

   A seed sprouts 60% of the time. In Jun's 20 copied tries of 2 seeds, 8 had both sprout. How many percentage points is the estimate from the exact chance?

   4

4. Read this first

   Use this

   0 to 5 is a sprout; 6 to 9 is not. Three digits make one try. Tries: 443, 801, 435, 898, 921, 304, 647, 180, 541, 739, 331, 272, 236, 200, 668, 682, 646, 517, 556, 528.

5. 4.

   A seed sprouts 60% of the time. Kira copies planting 3 seeds with random digits. From these 20 tries, what is the estimated chance at least 2 sprout, in simplest form?

   7/10

6. Use this

   0 to 2 is a make; 3 to 9 is a miss. Three digits make one try. Tries: 274, 603, 284, 128, 173, 851, 400, 385, 546, 115, 898, 773, 232, 939, 012, 042, 491, 319, 486, 841.

7. 5.

   Luz makes 30% of long shots and copies 3 shots with random digits. From these 20 tries, what is the estimated chance of at least one make, in simplest form?

   7/10

8. Marbles

   1, 2, 3 are red; 4, 5 are blue. Other digits and repeats were skipped, so each try is two different marbles. Tries: 25, 21, 32, 14, 15, 51, 13, 24, 34, 42, 31, 12, 45, 23, 12, 42, 24, 45, 34, 24.

9. 6.

   Pia's bag has 3 red and 2 blue marbles. Pia copies drawing 2 without looking or putting back, using random digits. From these 20 tries, what is the estimated chance of one of each color?

   11/20

10. Marbles

    1, 2, 3 are red; 4, 5 are blue. Other digits and repeats were skipped, so each try is two different marbles. Tries: 25, 35, 13, 14, 25, 35, 14, 41, 12, 24, 54, 53, 14, 35, 14, 54, 15, 43, 35, 21.

11. 7.

    Ren's bag has 3 red and 2 blue marbles. Ren copies drawing 2 without looking or putting back, using random digits. From these 20 tries, what is the estimated chance of at least one red?

    9/10
12. 8.

    Tala's bag has 3 red and 2 blue marbles. Tala draws 2 without looking, and the first is not put back. Which plan copies one draw of 2 with random digits?

    • One digit, 1 to 5, for the whole draw
    • Digits 1 to 5 are the marbles; skip 0, 6 to 9 and repeats
    • Digits 1 to 5 are the marbles; repeats are fine because each draw is separate
13. 9.

    Zee's class draws 2 of 4 names from a hat without looking; the first is not put back. Which plan copies one draw with random digits?

    • Digits 1 to 4 are the names; repeats are fine since each pick stands alone
    • Digits 1 to 4 are the names; skip other digits and repeats
    • Digits 0 to 4 are the names; skip repeats
14. 10.

    Three lights on Bo's route are green 50%, 30% and 20% of the time. Which plan copies one trip past all three with random digits?

    • One digit: 0 to 4 means all three are green
    • Three digits: 0 to 4 mean green for each light
    • Three digits: 0 to 4, then 0 to 2, then 0 and 1 mean green