If x_1, x_2, …, x_n and 1/(h_1), 1/(h_2), …, 1/(h_n) are two A.P.s such that x_3= h_2=8 and x_8= h_7=20, then x_5 · h_10 equals:

If $\displaystyle x_1, x_2, \ldots, x_{\mathrm{n}}$ and $\displaystyle \frac{1}{\mathrm{~h}_1}, \frac{1}{\mathrm{~h}_2}, \ldots, \frac{1}{\mathrm{~h}_{\mathrm{n}}}$ are two A.P.s such that $\displaystyle x_3=\mathrm{h}_2=8$ and $\displaystyle x_8=\mathrm{h}_7=20$, then $\displaystyle x_5 \cdot \mathrm{~h}_{10}$ equals :