1. The problem statement, all variables and given/known data Three balls are drawn one after the other with replacement, from a bag containing 5 red, 9 white and 4 blue identical balls. What is the probability that they are one red, one white and one blue? 2. Relevant equations 3. The attempt at a solution The question demands that I evaluate the probability that they are one red, one white and one blue balls in the three draws held. They did not give the order which the draws will follow, I therefore assume it could be in order. Here is my working: Total number of balls = 18 P(r) = 5/18 P(w) = 9/18 = 1/2 P(b) = 4/18 = 2/9 The probability that they are one red, one white and one blue balls = P(1st-r,2nd-w,3rd-b) Or P(1st-w,2nd-b,3rd-r) Or P(1st-b, 2nd-r,3rd-w) (5/18*1/2*2/9) + (1/2*2/9*5/18) + (2/9*5/18*1/2) = 10 + 10 + 10/324 = 30/324 = 5/54 But the answer I got did not match with the answer they provided for the question. Is my working wrong or did I not follow the right principle?