2005 Pascal Problem 6

A glass filled with water has a mass of 1000 g. When half the water is removed from the glass, the mass of the glass and the remaining water is 700 g. What is the mass of the empty glass?

\textbf{(A)}\ 600 \text{ g}\quad \textbf{(B)}\ 500 \text{ g}\quad \textbf{(C)}\ 350 \text{ g}\quad \textbf{(D)}\ 400 \text{ g}\quad \textbf{(E)}\ 300 \text{ g}

If there are no answer choices shown, enter a numerical answer.

Full credit to this problem is given to the CEMC, you may view all Pascal contests here.