Question

A small pouch contains 8 black marbles,5 white marbles, and 12 red marbles. Find the probability of picking a red then a black marble if you do not replace the first marble.

Answer 1

4/25

Explanation:

Total amount of marbles: 8 + 5 + 12 = 25

With 25 marbles, the probability of picking a red is: 12/25

After 1 red marble is removed, the probability of picking a black is: 8/24 = 1/3

Then, the probability of picking a red then a black marble if you do not replace the first marble is: 12/25 * 1/3 = 4/25