\noindent\textbf{106.} Behrouz can complete a magazine alone in 9 hours, and Farhad can complete it alone in a shorter time. If they work together, they finish the job in 20 hours. In how many hours can Behrouz complete this job alone?
\hfill (1) $32$ \hfill (2) $33$ \hfill (3) $35$ \hfill (4) $36$
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