A drawer contains 3 white balls and 6 black balls. Two balls are drawn out of the box at random. What is the probability that they both are black?
+486 The probability that the first one is black is $\frac{6}{9}=\frac{2}{3}$.
The probability that the second one is black is $\frac{5}{8}$.
Multiplying these together gives $\frac{2}{3}*\frac{5}{8}=\frac{10}{24}=\boxed{\frac{5}{12}}$ which is $41.\overline{6}$ percent
