Discussion Forum

A box B₁ contains 1 white ball, 3 red balls and 2 black balls. Another box B₂ contains 2 white balls, 3 red balls and 4 black balls. A third box B₃ contains 3 white balls, 4 red balls and 5 black balls.

If 1 ball is drawn from each of the  boxes B₁,B₂ and B₃  the probability that all 3 drawn  balls are of the same colour is 

Answer:

Explanation:

P (All 3 drawn balls are of the same colour) 

=  P(www)+P(RRR)+P(BBB)

    $=(\frac{1}{6}\times\frac{2}{9}\times\frac{3}{12})+(\frac{3}{6}\times\frac{3}{9}\times\frac{4}{12})$

    $+(\frac{2}{6}\times\frac{4}{9}\times\frac{5}{12})=\frac{82}{648}$