Explanation:

- The speed ratio between the first and the second train is 2:7.

- The first train travels 250 km in 5 hours.

- Speed of the first train = \(\frac{250 \text{ km}}{5 \text{ hours}} = 50 \text{ km/h}\).

- Since the speed ratio is 2:7, let speeds be 2x and 7x.

- Given 2x = 50, solve for x: \(x = \frac{50}{2} = 25\).

- So, the speed of the second train = 7x = \(7 \times 25 = 175 \text{ km/h}\).

- The total speed is sum of both train speeds: \(50 + 175 = 225 \text{ km/h}\).

- Option 4: 225 km/h is the correct answer.