Given: 6 red balls, 5 white balls and 5 blue balls

We can select 3 red balls from 6 red balls in ⁶C₃ ways

Similarly, We can select 3 white balls from 5 white balls in ⁵C₃ ways

Similarly, We can select 3 blue balls from 5 blue balls in ⁵C₃ ways

∴ No. of ways of selecting 9 balls is ⁶C₃ ×⁵C₃ × ⁵C₃

⇒ ⁶C₃ ×⁵C₃ × ⁵C₃ =

⇒ ⁶C₃ ×⁵C₃ × ⁵C₃ =

∴ Number of ways of selecting 9 balls from 6 red balls, 5 white balls and 5 blue balls if each selection consists of 3 balls of each colour is ⁶C₃ ×⁵C₃ × ⁵C₃ = 2000