A cereal company is putting

11

1

1

of

33

3

3

prizes in each box of cereal. The prizes are evenly distributed so the probability of winning any given prize is always

1/31/3

1/3

1, slash, 3

.

Adam wonders how many boxes he should expect to buy to get all

33

3

3

prizes. He carried out

3232

32

32

trials of a simulation and his results are shown below. Each dot represents how many boxes it took to get all

33

3

3

prizes in that trial.

33

3

44

4

55

5

66

6

77

7

88

8

99

9

1010

10

1111

11

1212

12

1313

13

# of boxes purchased

Use his results to estimate the probability that it takes

99

9

9

or more boxes to get all

33

3

3

prizes.