You pick 2 marbles from the bag. You pick the second one without replacing the first marble.

Question

(2 green, 2 white, 2 red, 2 yellow, 2 blue)

1. P(red then blue)
2. P (green then yellow)
3. P(white then blue then white)

Answer 1

Let us first pick our variables to make this problem simpler:

G - green marble

W - white marble

R - red marble

Y - yellow marble

B - blue marble

Using the letters we can make the bag of marbles look like this:

GG WW RR YY BB

There are a total of 10 marbles in the bag if you count the letters.

Each time we pick a marble out of the bag this event is independent. When we have independent events we multiply the probabilities together.

1. P(red then blue)= (2/10)(2/9)= .044

2. P(green then yellow)= (2/10)(2/9)= .044

3. P(white then blue then white)= (2/10)(2/9)(1/8)= .006