So the total amount of days in three weeks is 21. Every 21 days, it rains 7 days. We can write out a ratio the same way for every 366 days.
\(\frac{7}{21}=\frac{n}{366}\)
Now we solve for \(n\) (\(n \) being the number of days it rains in 366 days) by cross-multiplying. \(n=\frac{7\times366}{21}\Rightarrow \frac{366}{3}\Rightarrow 122\).
So our answer is \(\boxed{122}\)
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