Answer
$L = 2.5\times 10^{-7}~H$
Work Step by Step
We can find the inductance:
$f = \frac{1}{2\pi~\sqrt{LC}}$
$f^2 = \frac{1}{4\pi^2~LC}$
$L = \frac{1}{4\pi^2~C~f^2}$
$L = \frac{1}{(4\pi^2)~(10\times 10^{-12}~F)~(100\times 10^6~Hz)^2}$
$L = 2.5\times 10^{-7}~H$