arithmetic - a bag contains 2 blue balls 3 green balls and 4 yellow balls in how many ways can 3 balls be drawn from the bag if at least one green ball is to be included in the draw - skillgun

From 2 blue balls, 3 green balls and 4 yellow balls, 3 balls are to be selected such that
at least one green ball should be there.
Hence we have 3 choices
All three are green
Two are green and one is non green
One is green and two are non green
Total number of ways
= 3C3 + (3C2 x 6C1) + (3C1 x 6C2) [because 6 are non green]
=1+[3×6]+[3×15]=1+18+45=64