Question

Two cards are drawn without replacement from an ordinary deck, find the probability that the second is not a red card, given that the first is a red card?

What is the conditional probability?

Answer 1

first is a red card: 1/2
second is not a red card: 26/51
so the conditional probablity is 1/2 x 26/51, or 26/102. About 25.5%

Answer 2

how many cards left in the deck?
how many are red?
there are 51 cards left in the deck because you picked one
there are 26 black cards because you picked a red one
answer is \(\frac{26}{51}\)

Answer 3

btw \(\frac{26}{51}\) is not the probability that the second card is black. it is the probability that the second card is black GIVEN that the first card is red

Answer 4

oh...ok