A $5 \mathrm{~m} \times 5 \mathrm{~m}$ closed tank of $10 \mathrm{~m}$ height contains water and oil, and is connected to an overhead water reservoir as shown in the figure. Use $\gamma_{w}=10 \mathrm{kN} / \mathrm{m}^{3}$ and Specific gravity of oil $=0.8$.
The total force (in $\mathrm{kN}$ ) due to pressure on the side PQR of the tank is $\_\_\_\_\_\_$. (rounded off to the nearest integer).