Heat And Thermodynamics

A thermometer bulb has volume $10^{-6} \mathrm{~m}^3$ and cross-section of the stem is $0.002 \mathrm{~cm}^2$. The bulb is filled with mercury at $0^{\circ} \mathrm{C}$. If the thermometer reads temperature as $100^{\circ} \mathrm{C}$, then the length of mercury column is (coefficient of cubical expansion of mercury $=18 \times 10^{-5} /{ }^{\circ} \mathrm{C}$ )