1. **Stating the problem:** A green light flashes every 12 minutes. We want to understand the timing pattern of these flashes. 2. **Formula and explanation:** The green light flashes periodically every 12 minutes. This means the flashes occur at times that are multiples of 12 minutes, i.e., at $0, 12, 24, 36, \ldots$ minutes. 3. **Mathematical representation:** We can represent the time of the $n$-th flash as: $$t_n = 12n$$ where $n$ is a non-negative integer ($n=0,1,2,3,\ldots$). 4. **Interpretation:** This formula means the first flash is at $t_0=0$ minutes, the second at $t_1=12$ minutes, the third at $t_2=24$ minutes, and so on. 5. **Summary:** The green light flashes every 12 minutes, and the times of flashes follow the sequence $12n$ minutes for $n=0,1,2,\ldots$.