A U-tube in which the cross-sectional area of the limb on the left is one quarter, the limb on the right contains mercury (density $13.6 \mathrm{~g} / \mathrm{cm}^3$ ). The level of mercury in the narrow limb is at a distance of $36 \mathrm{~cm}$ from the upper end of the tube. What will be the rise in the level of mercury in the right limb if the left limb is filled to the top with water <br>