1. **State the problem:** A train of length 70 m is moving at a speed of 30 m/s and passes through a station of length 170 m. We need to find the time it takes for the train to pass completely through the station. 2. **Understand the concept:** To pass completely through the station, the train must cover the distance equal to the length of the train plus the length of the station. 3. **Formula used:** Time $t$ is given by the formula $$t = \frac{\text{distance}}{\text{speed}}$$ 4. **Calculate the total distance:** $$\text{distance} = 70 + 170 = 240 \text{ meters}$$ 5. **Calculate the time:** $$t = \frac{240}{30} = 8 \text{ seconds}$$ 6. **Answer:** The train takes 8 seconds to pass completely through the station.