Fluid A is water $(=1000\frac{kg}{m^3}),$ fluid $B$ is engine oil $(=884\mathrm{.}1\frac{kg}{m^3}),$ fluid $C$ is a liquid having specific

gravity of $1\mathrm{.}55,$ and fluid $D$ is air. Assume a density of water equal to $1000k\frac{g}{m^3}$ and a temperature of

$300K$ for other thermophysical properties. The elevations are $z_1=4cm,z_2=3cm,z_3=6cm,z_4=3cm,z_5$

$=8cm,$ and $z_6=5cm.$

Determine the gage pressure of air, in kPa, if the hydrostatic pressure at the bulb encompassing fluid $A$

is equal to $180$kPa $($gage$).$ Note the location in the bulb where the pressure is equal to $180$kPa $($gage$)$ is

at the bottom tick$-$mark corresponding to the dimension $z_1.$