Using the letters $A,C,E,F,I,H,O,P,S,$ and $T$ (with no repetition),how many $4$ unique letter grouping can be created that:
a) Start with $A,C,E$ or end with $C,E,S,T$ ?
my approach is: $3$ choices for the first letter then 4 choices for the last letter,now i have used only $2$ letters, so we are left with 8 letters.
$(3)(8)(7)(4)= 672$
However, it does not match the answer that I have.Most likely the word "or" causing me a problem
Help would be appreciated
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