A bag contains 4 red, 3 black and 2 white balls. In how many ways

3 balls can be drawn from this bag so that they include at least one

black ball?​

Dear Student

Required number of ways = Number of ways of selecting 3 balls out of given 9 balls (without any restriction) - Number of ways of selecting 3 balls when no black ball is to be selected.
Hence the answer should be
9C3−6C3
9C3−6C3
= 84 - 20
= 64


Thanks