Условная вероятность

Two balls are drawn from an urn containing two white and six black balls. What is the probability that both balls are black? ➖➖➖➖➖➖➖➖➖➖➖➖➖➖➖ We're looking at our subscribers' challenges! ➖➖➖➖➖➖➖➖➖➖➖➖➖➖➖ The next challenge can be yours. To do this, you need to: 1. Be subscribed to our channel (subscription information is open). 2. Write a topic of interest or the conditions of your challenge in the comments. ➖➖➖➖➖➖➖➖ Subscribe to the channel:    / @on-line-it6xk   ➖➖➖➖➖➖➖➖