An urn contains 5 white, 6 red and 4 blue balls. Three balls are drawn at random. What is the probability that a white ball, a red ball and a blue ball are drawn?

Step-by-step solution

Total number of balls in the urn = 5 + 6 + 4 = 15 Total number of ways to draw 3 balls from 15 balls = ¹⁵C₃ = 15 14 13 3 2 1 = 455 Number of ways to draw 1 white, 1 red and 1 blue ball = ⁵C₁ ⁶C₁ ⁴C₁ = 5 6 4 = 120 Required probability = 120 455 = 24 91