Three dices thrown, Total outcomes when three dice drawn is =6×6×6=216 Total outcomes of triplets is (1,1,1),(2,2,2),(3,3,3),(4,4,4),(5,5,5),(6,6,6) Probability of triplet when three dice thrown once is =
6
216
=
1
36
Required probability on throwing three throws of three dice not more than twice, ⇒P(x=0)+P(x=1)+P(x=2) ⇒3C0(