How to solve

Determine the difference in pressure $P_A-P_B$ between the centres A and $B$ of the closed pipes, which are filled with kerosene. The mercury in the inclined$-$tube manometer has the level as shown in Figure Q$2.$ Take the specific gravity of mercury and kerosene as $S_{Hg}=13\mathrm{.}55$ and $S_k=0\mathrm{.}82,$ respectively. Neglect the inclined angle.

Figure Q$2$: Schematic of inclined$-$tube manometer