Question

What is the probability of drawing a red card, not replacing it, and then drawing another red card? there are 2 red cards and 3 blue cards

Answer 1

1/10 is the answer.

Explanation:

Answer 2

Let's analyse both scenarios: for the first pick, you have 5 cards in total, of which 2 are red. So, you have a chance of 2/5 of picking a red card.

Now, assume you picked a red card with the first pick. The new scenario will be different, now there are only 4 cards in total (since you didn't replace the first picked card), of which only 1 is red. This means that you have a chanche of 1/4 of picking a red card.

Once you figured the probabilities of both events, if you want to compute the probability of the two events happening one after the other, you simply have to multiply them, so you have

`\cfrac{2}{5} \cdot \cfrac{1}{4} = \cfrac{2}{20} = \cfrac{1}{10}`