Solution of problem N4329 probability theory

Sold 0
Refunds 0
Good feedbacks 0
Bad feedbacks 0

4329. There are 10 white and 15 black balls in the box. Two balls are taken out in turn, and the first is not returned back. What is the probability that they will be taken out:
a) both balls are black
b) both balls are white
c) multi-colored balls
Detailed solution. Decorated in Microsoft Word 2003 (Quest decided to use the formula editor)