A bowl contains 7 white pebbles and 5 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?

2 out of 12

Step-by-step explanation:

7+5= 12 (which is the total)

if one white and black pebble is choose so it will be 2 out of 12

35/132

Step-by-step explanation:

7 white pebbles, 5 black pebbles

7 + 5 = 12

12 pebbles total

First drawing:

p(white) = 7/12

Second drawing:

The white pebble was not replaced, so the total now is 11 pebbles.

p(black) = 5/11

p(white then black) = 7/12 * 5/11 = 35/132

2500

step-by-step explanation: