$\begin{align}  & {{E}_{1}}=k\frac{\left| q \right|}{r_{1}^{2}}=k\times \frac{q}{{{3}^{2}}}=\frac{k}{9}q\,\,(\frac{N}{C})\,\,\,\,\,\,\,\,\,(1) \\  & {{E}_{2}}=k\frac{\left| q \right|}{r_{2}^{2}}=k\times \frac{q}{{{2}^{2}}}=\frac{k}{4}q\,\,(\frac{N}{C}) \\  & {{E}_{2}}-{{E}_{1}}=250\,\,(\frac{N}{C})\,\Rightarrow \frac{kq}{4}-\frac{kq}{9}=\frac{5}{36}kq=250 \\  & \Rightarrow kq=1800\,\,(\frac{N{{m}^{2}}}{C})\,\,\,\,\,\,\,(2) \\  & \xrightarrow[{}]{(1),(2)}{{E}_{1}}=\frac{kq}{9}=\frac{1800}{9}=200\,\,\,(\frac{N}{C}) \\ \end{align}$