Question

A bag contains five white marbles and five black marbles. What is the probability of drawing a WHITE marble, NOT replacing it, and then drawing another WHITE marble?

Answer 1

4/18

Explanation:

You have 5 WHITE marbles and 5 Black marbles.

The probability of drawing a WHITE marble is 5/10 or 1/2

And the probability of drawing the second (marble another WHITE marble) is 4/9

So 1/2 x 4/9 = 4/18 or 5/10 x 4/9 = 20/90 / 5 = 4/18

Therefore the probability of drawing a WHITE marble not replacing it then drawing another WHITE marble is 4/18

Answer 2

The probability is 1:2