Question

A jar contains black and white marbles. Two marbles are chosen without replacement.

The probability of selecting a black marble and then a white marble is 0.34, and the

probability of selecting a black marble on the first draw is 0.47. What is the probability

of selecting a white marble on the second draw, given that the first marble drawn was

black?

Answer 1

$P(White|Black) = \frac{P(Black \;and \; White)}{P(Black)} \\ = \frac{0.34}{0.47} \\ = 0.723 \\ = 72.3 \; \%$