Answer (13 of the original arrangements are duplicates now, as
AAAF F F FDDDDCC, AAF F F FDDDDCCA, ..., CAAAF F F FDDDDC
are identical): 900900/13 = 69300.
Well, since you have two variables in one equation, you would have to have at least one other equation to solve this problem. Their isn't enough information to solve this alone, sorry :/
Why don’t you round the last answer
2/10 in simplest form is 0.2