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.

   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

2. 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.

3. 2.

   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

4. Use this

   0 to 7 is a goal; 8 and 9 are misses. Three digits make one try. Tries: 544, 133, 607, 348, 585, 025, 277, 084, 265, 755, 297, 924, 067, 539, 154, 079, 930, 810, 068, 822.

5. 3.

   Milo scores on 80% of penalty kicks and copies 3 kicks with random digits. From these 20 tries, what is the estimated chance all 3 are goals, in simplest form?

   9/20

6. Marbles

   1, 2, 3 are red; 4, 5 are blue. Other digits and repeats were skipped, so each try is two different marbles. Tries: 51, 34, 32, 13, 14, 53, 23, 51, 42, 23, 23, 41, 25, 52, 15, 45, 34, 12, 32, 32.

7. 4.

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

   2/5

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. 5.

   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. 6.

    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. 7.

    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?

    • Digits 1 to 5 are the marbles; repeats are fine because each draw is separate
    • Digits 1 to 5 are the marbles; skip 0, 6 to 9 and repeats
    • One digit, 1 to 5, for the whole draw
13. 8.

    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; skip other digits and repeats
    • Digits 0 to 4 are the names; skip repeats
    • Digits 1 to 4 are the names; repeats are fine since each pick stands alone
14. 9.

    Ari makes 75% of free throws and 45% of long shots. Which plan copies one free throw and one long shot with random two-digit numbers 00 to 99?

    • First pair: 00 to 75 is a make. Second pair: 00 to 45 is a make.
    • Both pairs: 00 to 74 mean a make
    • First pair: 00 to 74 is a make. Second pair: 00 to 44 is a make.
15. 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, then 0 to 2, then 0 and 1 mean green
    • Three digits: 0 to 4 mean green for each light