A box contains 5 white balls and 6 black balls. Two balls are drawn out of the box at random. What is the probability that they both are white?

Guest May 27, 2019

#1**+1 **

5 + 6 means there are **11 balls in total**.

Of these 11, 5 are white, so the probability of the first ball that's drawn being white is **5/11**.

I'll assume the ball isn't put back into the box. So now you have 10 balls left, 4 of which are white.

('cause you already removed one white ball, the total number of balls and the number of white balls goes down)

Which means that the second pull has a **4/10 **chance of being a white ball.

*Both* of these events need to happen, so you multiply the chances:

**(5/11) * (4/10) = 2/11**

Guest May 27, 2019