An auction with ties

The previous close is ₹250. At the end of order entry the book is:

(a) Tabulate $D$, $S$, $V$ and $|D-S|$ at each limit price and find the equilibrium price, volume and imbalance. (b) Which orders execute, and what rests in the book when continuous trading starts? (c) Now reduce the sell at ₹251 to 500 shares. Find the equilibrium price when the previous close is ₹250, and when it is ₹251.20.