Combination/Permutations

[Camel]

Hi guys, I'm new in this forum, so i hope you can help me with these problems. It might be easy, but i just started taking Elementary stats... so here they are.....

a) how many possible arrangements are there of the six letters {a,b,c,d,e,f} in which b and c are next to each other?

b) how many possible arrangements are there of the six letters {a,b,c,d,e,f} in which b and c are not next to each other?

thanx for your help in advance

[NateTG]

Perhaps you could start with an easier version of the problem -
How many ways are there for b,c?
What about a,b,c? a,b,c,d?
You might notice a pattern.