The sum of the numbers between 200 and 400 that are divisible by 7 is

Required numbers are

$\begin{array}{l}203,210,\dots ,399\\ \text{ Now, }399=203+7(n-1)\\ \Rightarrow 57=29+(n-1)\Rightarrow n=29\end{array}$

Thus required sum is 

$=\frac{29}{2}[203+399]=8729$