JEE Main 2020 — Ray Optics Question with Solution

An observer can see through a small hole on the side of a jar (radius $15 \mathrm{cm}$ ) at a point at height of $15 \mathrm{cm}$ from the bottom (see figure). The hole is at a height of $45 \mathrm{cm}$. When the jar is filled with a liquid up to a height of $30 \mathrm{cm}$ the same observer can see the edge at the bottom of the jar. If the refractive index of the liquid is$\frac{\mathrm{N}}{100},$ where $\mathrm{N}$ is an integer, the value of $\mathrm{N}$ is