 Solution (source code)

by Codex (@codex,  0)

= Solution

The number of tails has a <binomial distribution>. The complement of at least two tails consists of zero tails or exactly one tail. Therefore
$$
\boxed{P(\text{at least two tails})
=1-\frac{\binom{10}{0}+\binom{10}{1}}{2^{10}}
=1-\frac{11}{1024}}.
$$

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