When rolling 5 dice, what is the probability of rolling at least one 6, one 5, and one 4.

Is there a Formula Such as P=(1/6)x(1/6)x(1/6)+(1/6)x(1/6). I know the probability

of rolling one of each with 3 dice is 1/216. I don't know how to compute the

additional probability of the other two dice. I am looking for the most basic way to do the math.

Thanks

Del