A bag has 6 white and 4 black balls. 3 are drawn at random together. What is the probability that exactly 2 are white?

Explanation

1. 01

   Total ways: ${}^{10}C_3 = 120$. Favourable: ${}^{6}C_2 \times {}^{4}C_1 = 15 \times 4 = 60$.

2. 02

   $\frac{60}{120} = \frac{1}{2}$.