Solution (source code)

= Solution

A double six has <probability> $p=1/36$ on each independent throw. For Alice to win on her second turn, her first throw and Bob's first throw must both fail, then her second throw must succeed. Therefore
$$
\boxed{P=\left(\frac{35}{36}\right)^2\frac1{36}=\frac{1225}{46656}}.
$$