How many arrangements of $MATHEMATICAL$ are there in which $ME$ appear together but the $ME$ is not immediately followed by an $A$? (no MEA)
The answer is $(11!)/(3!2!) - (10!)/(2!2!)$
I am confused as to how this is the answer. There are 12 letters in $MATHEMATICAL$. I also don't understand the denominators. Is the first for the combinations of MEA and ME and the second is just ME and ME? There are $2$ M's and $1$ E.