A box contains 5 blue, 4 red, and 3 yellow marbles. Two marbles are randomly drawn and not replaced. What is the probability of drawing a blue then a red marble?

Question

asked Feb 20, 2021 104k views

2 Answers

Chris Grimm · Answer 1 · 2021-02-25T18:59:33+0000

Answer: Probability = 20/132

Step-by-step explanation: There is no replacement in the box, so, once the marble is taken out, there will be one less inside the bag:

Total = 5 + 4 + 3 = 12

Probability of Blue:

P(b) = 5/12

Probability of Red: Since the blue is already out, total will be one less:

P(r) = 4/11

Probability of taken one and then the other:

P(blue,red) =
(5)/(12) . (4)/(11)

P(blue,red) =
(20)/(132) ≈ 0.15

The probability of drawing a blue and then a red is 20/132.