A pulp screen is fed with $50000\frac{m^3}{d}$ of stock at $1\%$ consistency. The feed pulp has a long fibre fraction of $20\%$ and a shive content of $0\mathrm{.}5\%.$ The screen accepts flow is at $0\mathrm{.}8\%$ consistency, with a long fibre fraction of $28\%$ and a shive content of $0\mathrm{.}1\%.$ The consistency of the reject stream is $1\mathrm{.}3\%.$ Calculate the following screen performance characteristics:

a$)$ Volumetric reject rate