7. (10 points) The Spring Festival is approaching. Starting from January 17, 2011 (Monday), workers in the factory gradually return home for the New Year to reunite with their families. If the number of workers leaving the factory each day is the same, by January 31, there are still 121 workers left in the factory. During this 15-day period, the total workdays (one person working one day counts as 1 workday, and workers do not need to be counted after they leave the factory) recorded in the factory is 2011 workdays, with weekends off and no one absent. How many workers have returned home by January 31? $\qquad$
【Solution】Solution: According to the problem, we have:
Let the number of people returning home each day be $x$ people, then in 15 days, a total of $15 x$ people will return home,
with 2 Saturdays and Sundays, a total of 4 days off without working. The remaining number of people on weekends is $9 x$ (Saturday), $8 x$ (Sunday), $2 x$ (Saturday), $x$ (Sunday).
$$
\begin{array}{l}
121 \times 11+(3+4+5+6+7+10+11+12+13+14) x=2011 \\
\therefore x=8, \quad 15 x=120 \text { (people) }
\end{array}
$$

Therefore, the answer is: 120