Five friends, A,B,C,D and D, stand in a line for a photograph.

1) How many different possible arrangements are there if A , B and C stand next to each other?

2) How many different possible arrangements are there if none of A, B and C stand next to each other?

3) if all possible arrangements are equally likely, find the probability that two of A, B and C are next to each other, but the third is not next to either of the other two.