Let $X=\{\mathrm{x} \in \mathrm{N}: 1 \leq \mathrm{x} \leq 17\}$ and $\mathrm{Y}=\{\mathrm{ax}+\mathrm{b}: \mathrm{x} \in \mathrm{X}$ and $\mathrm{a}, \mathrm{b} \in \mathrm{R}, \mathrm{a}>0\} .$ If mean and variance of elements of $Y$ are $17$ and $216$ respectively then $a + b$ is equal to 

  • [JEE MAIN 2020]
  • A

    $-7$

  • B

    $7$

  • C

    $9$

  • D

    $-27$

Similar Questions

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  • [JEE MAIN 2023]

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  • [JEE MAIN 2020]