Current Attempt in Progress

$($Manometer$)$ A mercury $($specific weight $=847l\frac{b}{f}{t}^3)$ manometer is used to measure the pressure difference in the two pipelines of

the figure below. Fuel oil $($specific weight $=53\mathrm{.}0l\frac{b}{f}{t}^3)$ is flowing in A and SAE $30$ lube oil $($specific weight $=57\mathrm{.}0l\frac{b}{f}{t}^3)$ is flowing in $B.$

An air pocket has become entrapped in the lube oil as indicated. Determine the pressure in pipe $B$ if the pressure in $A$ is $15\mathrm{.}5$ psi.