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Arrangements with Separations

Combinatorics 1167
Janne and JD, among ten other party attendees, were asked to fall in line. What is the probability that there will be at least five attendees between Janne and JD? The answer is in the form $\frac{\alpha}{\beta}$ for some coprime integers $\alpha$ and $\beta$. Input the value of $\alpha+\beta$.