If $x_1 , x_2 ,  ..... , x_n$ and $\frac{1}{{{h_1}}},\frac{1}{{{h^2}}},......\frac{1}{{{h_n}}}$ are two $A.P' s$ such that $x_3 = h_2 = 8$ and $x_8 = h_7 = 20$, then $x_5. h_{10}$ equals

  • [JEE MAIN 2018]
  • A

    $2560$

  • B

    $2650$

  • C

    $3200$

  • D

    $1600$

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