JEE Main 2013 — Wave Optics Question with Solution

A person lives in a high-rise building on the bank of a river $50\mathrm{m}$ wide. Across the river is a well lit tower of height $40\mathrm{m}$. When the person, who is at a height of $10\mathrm{m}$, looks through a polarizer at an appropriate angle at light of the tower reflecting from the river surface, he notes that intensity of light coming from distance $\mathrm{X}$ from his building is the least and this corresponds to the light coming from light bulbs at height ' $\mathrm{Y}$ ' on the tower. The values of $\mathrm{X}$ and $\mathrm{Y}$ are respectively close to (refractive index of water $\simeq \frac{4}{3}$ )