There are 5 cards with a picture of a rose and 1 card with a picture of a daisy. Olga keeps all the cards face down on the table with the pictures hidden and mixes them up. She then turns over one card and finds the picture of a rose on it. She removes this card from the table and turns over another card without looking. What is the probability that the card that Olga turns over has a rose on it?

1/5
4/6
4/5
5/6

Question

There are 5 cards with a picture of a rose and 1 card with a picture of a daisy. Olga keeps all the cards face down on the table with the pictures hidden and mixes them up. She then turns over one card and finds the picture of a rose on it. She removes this card from the table and turns over another card without looking. What is the probability that the card that Olga turns over has a rose on it?

 1/5
 4/6
 4/5
 5/6

anonymous · Answer

So, there are 6 cards in total. For the first card, what is the probability of flipping a rose?

anonymous · Answer

so the answer is she removed a rose card already. how many cards total will be your bottom variable how many cards remaining have roses will be your top variable

anonymous · Answer

would it be 5/6?

anonymous · Answer

no 4/5

anonymous · Answer

There are 5 roses and 6 cards in total. So the probability of choosing a rose on the first flip is 5/6. OK with that?

anonymous · Answer

OK

anonymous · Answer

so my answer is 4/5 right?

anonymous · Answer

Now, the first card is removed, so there remains 4 roses and 1 daisy left (a total of 5 cards). On this secon flip, what is the probability of flipping a rose?

anonymous · Answer

5

anonymous · Answer

you have removed a card already so that card no longer counts
ie
$$5r+1l=6total$$
$$5r-1r=4r+1l=5t$$
so 4r/5t

anonymous · Answer

oh OK thank you!

anonymous · Answer

To get your final answer, you multiply the two individual probabilities together.$$P_{A \text{ then }B} = P_A \times P_B$$