A box contains 2 white balls, 3 black balls and 4 red balls. What is the number of ways of drawing 3 balls from the box with at least one black ball?

Step-by-step solution

W =2, ~B =3, R =4 Total balls =2+3+4=9 Number of ways of drawing 3 balls with at least one black ball aligned & = ^3 C₁ ^6 C₂+ ^3 C₂ ^6 C₁+ ^3 C₃ & =45+18+1=64 aligned