probability and statistics problem?

a train is pulling 3 wagons, 3 with chemicals, 2 with steel and 3 with animals. in how many different ways can we order them if there wagons with animals can't be next to a wagon with chemicals??? There is no difference between every wagon of the same thing, like... c1 c2 c3 s1 s2 a1 a 2 a3 and c3 c2 c1 s2 s1 a3 a2 a1 would be the same, it just goes like c c c s s a a a

8...just a wild guess though...probably wrong.

If he has to pick one of every type, then the answer is 2.If he can have more than one of each type, ie: c c s, then the answer is 5.Next time, be more clear and specific on your problems.Hope that helped.