The three$-$liquid system below is in equilibrium. The specific gravities of the mercury and oil are $13\mathrm{.}55$ and $0\mathrm{.}83$ respectively. Calculate the total weight of the liquids on vertical tubes if the cross sectional area of the tube is $2$ sq$.$m$.$

a$\mathrm{.}4\mathrm{.}2$ N

b$.9\mathrm{.}1$ N

C$\mathrm{.}7\mathrm{.}2$ N

d$.2\mathrm{.}4$ N