Question

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?

Answer 1

5/33

Explanation:

Answer 2

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.