Question

Brianna has a bag of marbles that are all the same size. Of all the marbles in the bag, there are 6 red, 7 white, 3 black, and 4 green marbles.





Write a probability model for this experiment, and use the probability model to predict how many times Brianna would pick a green marble if she chose a marble 50 times. Give the probabilities as simplified fractions.



Drawing a red marble



Drawing a white marble



Drawing a black marble



Drawing a green marble



Brianna would draw
green marbles in 50 tries.

Answer 1

Total marbles = 6 + 7 + 3 + 4 = 20.

Probability model (simplified fractions):
- Drawing a red marble: 6/20 = 3/10
- Drawing a white marble: 7/20
- Drawing a black marble: 3/20
- Drawing a green marble: 4/20 = 1/5

Expected number of green marbles in 50 draws = 50 × (1/5) = 10.

Brianna would draw 10 green marbles in 50 tries.