I'll give this one a try ....though it doesn't appear to be too easy!!!
Notice that we could have these 2 configurations right off the bat......
yyyy zzzz xxxx and zzzz xxxx yyyy
Next, we could have this
yyyz xzzz xxxy .......but....since each single letter within each grouping can appear in one of four positions,
we have 4 x 4 x 4 = 64 possiblities
Next, we could have
yyzz xxzz xxyy ....notice that within each subgroup, we have (4!)/(2! * 2!) = 6 recognizable "words"
So 6 x 6 x 6 = 216 possibilities
We could also have
yzzz xxxz xyyy...which is again, 64 possibilities
So...if I haven't missed any combos, the total possible "words" = 2 + 2(64) + 216 = 346
Could somebody else check this....(Melody, Alan, heureka ??)
