Answer
$$1.5 \times 10^3 \space Pa$$
Work Step by Step
Hydrostatic pressure = $\rho gh$
$\rho = 1.0 \space g/cm^3 \longrightarrow 1.0 \frac{g}{cm^3} \times \frac{10^6 \space cm^3}{1 \space m^3} \times \frac{1 \space kg}{1000 \space g} = 10^3 \space \frac{kg}{m^3}$
$g = 9.81 \space m/s^2$
$h = 15 \space cm \longrightarrow 15 \space cm \times \frac{1 \space m}{100 \space cm} = 0.15 \space m$
$$\rho gh = (10^3 \space kg/m^3)(9.81 \space m/s^2)(0.15 \space m) $$ $$ \rho gh= 1.5 \times 10^3 \space \frac{kg}{ms^2} = 1.5 \times 10^3 \space Pa$$
