Question

From an urn containing 3 white and 2 black balls, two balls are drawn one after the other without replacement. What is the probability that the first ball drawn is white and the second black?

Answer 1

There is a 3/5 chance of the first ball being white, and a 3/10 chance the second one is black.

Explanation:

There are 5 balls, of which 3 are white, so you have a 3/5 chance of the first one being white. Then you have 2 white and 2 black balls. There is a 2/4 chance of picking a black ball. Multiply 3/5 and 2/4 to get 6/20, or 3/10 for choosing a white ball then a black ball.