A bowl contains 12 white pebbles and 7 black pebbles. A pebble is chosen and not replaced, then another pebble is picked. What is the probability that the first one is a white pebble and the second one a black pebble?

Answer 1

P(W) = 12/19
P(B) = 7/(19-1)
If the events are independent, the probability of both/all events occurring is determined by multiplying the probabilities of the individual events.