Question

A bag contains 2 red marbles and 3 blue marbles. What is the probability of drawing a red marble, keeping it, and drawing another red marble?

Answer 1

2/5, 1/4

Explanation:

The total amount of marbles before drawing a marble is 2+3=5. There are 2 red marbles. Thus, the theoretical probability of drawing a red marble from the bag is 2/5.

If you keep the red marble, there are now 4 total marbles in the bag. There is also only 1 remaining red marble. Thus, the theoretical probability of drawing a red marble is now 1/4.

Answer 2

Explanation:

the first marble has a probability of 2/5

the second marble has a probability of 1/4

P(r=2) = 2/5 * 1/4 = 2/20 = 1/10