1. **State the problem:** A train passes a station 120 m long at a speed of 180 km/h and takes 7 seconds to pass completely. We need to find the length of the train. 2. **Formula and concepts:** The total distance covered by the train while passing the station is the sum of the length of the train ($L$) and the length of the station (120 m). 3. **Convert speed to m/s:** Speed in m/s = $\frac{180 \times 1000}{3600} = 50$ m/s. 4. **Use the formula for distance:** Distance = Speed $\times$ Time. 5. **Calculate total distance:** Total distance = $50 \times 7 = 350$ m. 6. **Find the length of the train:** $L + 120 = 350 \Rightarrow L = 350 - 120 = 230$ m. **Final answer:** The length of the train is $230$ meters.