Commercial radio station call signs (i.e. WZZQ) are assigned following certain rules. The first letter must be either "W" or "K" and the last three letters can be anything as long as they aren't all the same. How many possible radio station call signs are possible?

How many different radio station call signs can you have with the first letter K and the second letter different from Q?

Question

Commercial radio station call signs (i.e. WZZQ) are assigned following certain rules.  The first letter must be either "W" or "K" and the last three letters can be anything as long as they aren't all the same.  How many possible radio station call signs are possible?

How many different radio station call signs can you have with the first letter K and the second letter different from Q?

anonymous · Answer

ok the answers are 35,100 and 16,875 
but I don't know how to get those answers.

directrix · Answer

>  last three letters can be anything as long as they aren't all the same

Are you saying that WXXX is not allowed but WXXY and WXWX are allowed?

anonymous · Answer

i found how to do it online... http://www.ms.uky.edu/~sohum/ma162/sp_10/lectures/lec13xalt.pdf

anonymous · Answer

but thanks :)

directrix · Answer

That is a good explanation of working the problem.