$($b$)$ A $\text{'}U\text{'}$ tube manometer shown in the Figure below is used to measure the pressure in a pipe which carries oil of relative density $0\mathrm{.}88.$ The lower manometer liquid is mercury of relative density $13\mathrm{.}6.$ The surface separation between the Oil and Mercury is $0\mathrm{.}93$ m below the centreline of the pipe. Take atmospheric pressure as $101k\frac{N}{m^2}.$ What is the gauge pressure at Point $A$ if $\text{'}h\text{'}$ is $37$ mm $.(5$ marks$)$give