Answer:
12.5 hours
Explanation:
To solve this problem, we can set up the following equation:
(distance traveled by diesel train) / (speed of diesel train) = (distance traveled by freight train) / (speed of freight train)
Substituting the given values and solving for the distance traveled by the diesel train, we get:
(distance traveled by diesel train) / 25 km/h = 10 hours / 40 km/h
Multiplying both sides of the equation by 25 km/h gives:
distance traveled by diesel train = (10 hours / 40 km/h) * 25 km/h
Simplifying this expression gives:
distance traveled by diesel train = 10 hours * (25 km/h / 40 km/h)
Which simplifies to:
distance traveled by diesel train = 10 hours * (5/8)
Therefore, the diesel train traveled for 10 * (5/8) = 1.25 * 10 = 12.5 hours before the freight train caught up.