We have Number of red balls = 6
Number of White balls = 6
Number of blue balls = 6
Since each selection consists of 3 balls of each = 11 colours, so 3 red balls can be selected out of 6 balls in 6C3 ways, 3 white balls out of 5 can be selected in 5C3 ways and 3 blue balls out of 5 can be selected in 5C3 ways
∴ Required number of ways = 6C3 x 5C3 x 5C3
= 20 x 10 x 10 = 2000