Fashionista

In the first example, the numbers of choices on successive days are $7$, $6$, $5$, $4$, and $6$, so the answer is $7 \times 6 \times 5 \times 4 \times 6=5040$.

In the second example, there are $7 \times 6 \times 6=252$ plans in which the same outfit is worn on days $1$ and $3$. There are $7 \times 6 \times 5 \times 5=1050$ plans in which different outfits are worn on those days, giving a total of .

In the third example, if the same outfit is worn on the first two days, there are $6$ choices for day $3$. If different outfits are worn, there are $5$ choices for day $3$. Thus, the answer is $7 \times 6 + 7 \times 6 \times 5=252$.