Use a simulation to estimate a compound chance

Answer Key - Grade 8 Math Worksheet

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

1. 1.

   20% of cereal boxes have a sticker and 50% have a coupon. Bo copies one box with 2 random digits: first sticker, then coupon. Which plan works?

   • First: 0 and 1 mean a sticker. Second: 0 to 4 mean a coupon.
   • Both digits: 0 and 1 mean yes
   • First: 0 to 2 mean a sticker. Second: 0 to 5 mean a coupon, both ends counted.
2. 2.

   A light is green 50% of the time, and a walk sign is on 30% of the time. Esme copies one trip with random digits. Which plan works?

   • Both digits: 0 to 4 mean yes
   • One digit: 0 to 4 mean green, and 0 to 2 mean walk
   • First digit: 0 to 4 mean green. Second digit: 0 to 2 mean walk.

3. Read this first

   Use this

   0 to 7 is a make; 8 and 9 are misses. Two digits make one try. Tries: 29, 18, 32, 40, 71, 00, 25, 30, 46, 75, 86, 56, 41, 19, 08, 44, 17, 50, 20, 86.

4. 3.

   Jun makes 80% of free throws and copies 2 shots with random digits. From these 20 tries, what is the estimated chance both are makes, in simplest form?

   7/10

5. Use this

   0 to 3 is a sprout; 4 to 9 is not. Two digits make one try. Tries: 98, 14, 97, 44, 15, 72, 58, 03, 71, 88, 60, 50, 40, 75, 67, 23, 65, 44, 21, 45.

6. 4.

   Old seeds sprout 40% of the time. Kira copies planting 2 with random digits. From these 20 tries, what is the estimated chance exactly one sprouts, in simplest form?

   7/20

7. First digit

   0 and 1 mean a sticker. Second digit: 0 to 4 mean a coupon. Tries: 09, 73, 20, 25, 01, 27, 06, 94, 49, 13, 20, 43, 64, 57, 25, 87, 70, 15, 03, 04.

8. 5.

   20% of cereal boxes have a sticker and 50% a coupon. From Luz's 20 copied boxes, what is the estimated chance a box has at least one, in simplest form?

   7/10

9. First digit

   0 to 4 mean green. Second digit: 0 to 2 mean walk. Tries: 19, 10, 28, 03, 17, 06, 73, 66, 05, 26, 03, 41, 17, 00, 38, 77, 69, 07, 94, 06.

10. 6.

    A light is green 50% of the time and a walk sign is on 30%. From Milo's 20 copied trips, what is the estimated chance of both, in simplest form?

    3/20

11. Use this

    0 to 7 is a make; 8 and 9 are misses. Two digits make one try. Tries: 66, 48, 82, 66, 78, 98, 09, 72, 93, 76, 50, 27, 49, 90, 57, 99, 20, 89, 68, 07, 43, 35, 63, 74, 33.

12. 7.

    Noah makes 80% of free throws and copies 2 shots with random digits. From these 25 tries, what is the estimated chance of at least one make, as a percent?

    88

13. First digit

    0 and 1 mean the bus is late. Second digit: 0 to 3 mean rain. Tries: 47, 36, 14, 22, 12, 92, 42, 29, 38, 18, 93, 97, 62, 12, 50, 14, 78, 53, 64, 42, 56, 41, 21, 44, 69.

14. 8.

    Ren's bus is late 20% of days, and it rains 40% of days. From these 25 copied days, what is the estimated chance of exactly one of the two, as a percent?

    52

15. Use this

    0 to 6 is a make; 7 to 9 is a miss. Two digits make one try. Tries: 90, 66, 71, 48, 80, 95, 09, 91, 23, 42, 77, 61, 40, 99, 26.

16. 9.

    Zee makes 70% of free throws and copies 2 shots 15 times. What is the estimated chance of exactly one make, to the nearest hundredth?

    0.47

17. Use this

    0 to 3 is gold; 4 to 9 is not. Two digits make one try. Tries: 04, 68, 86, 30, 88, 14, 03, 52, 36, 25, 17, 95, 46, 65, 84, 59, 18, 24.

18. 10.

    Ari's spinner has 10 equal parts, and 4 are gold. Ari copies 2 spins 18 times. What is the estimated chance of at least one gold, to the nearest hundredth?

    0.56