A figure skater started his spinning at $3re\frac{v}{sec}$ initially with rotational inertia $35kg{m}^2.$ Then he pulled his arms closer toward the center of his body to decrease the moment of inertia to $20kg{m}^2.$ What is the final spinning in rev$/$sec$?$

a$.5\mathrm{.}25re\frac{v}{s}$

b$.1\mathrm{.}71re\frac{v}{s}$

c$.3\mathrm{.}00re\frac{v}{s}$

d$.3\mathrm{.}14re\frac{v}{s}$