Question

You select a marble without looking and then put it back. If you do this 4 times, what is the best prediction possible for the number of times you will pick a green or a blue marble?

Answer 1

To predict the number of times a green or blue marble will be picked in 4 draws, calculate the probability for each draw and multiply by the number of draws. In this case, the best prediction is 2.

Step-by-step explanation:

To predict the number of times you will pick a green or a blue marble, you need to calculate the probability of picking a green or a blue marble in each individual draw and then multiply it by the number of draws.

In this case, the bag contains 4 blue and 3 white marbles. The probability of picking a blue or a green marble in each draw is (4 blue + 0 green) / (4 blue + 3 white) = 4 / 7.

Since you are doing 4 draws, the best prediction for the number of times you will pick a green or a blue marble is 4 x (4/7) = 16/7, which rounded to the nearest whole number is 2.