For the grinding circuit shown in the figure below, the material of specific gravity $3\mathrm{.}2$ is fed at the rate of $250$ tph$.$ If the ratio of solids underflow of cyclone to the fresh feed to the feed to the rod mill is $4$ and the $\%$ solids in overflow and underflow of cyclone by weight are $36\mathrm{.}5\%$ and $80\%$ respectively, Calculate

a$.$ percent solids by weight in the feed to the cyclone

b$.$ slurry tonnage of feed to the cyclone, overflow and underflow from the cyclone

c$.\%$ Solids by volume in feed