Two trains, measuring 200 meters and 150 meters, are traveling on parallel tracks at speeds of 40 km/h and 45 km/h, respectively. When moving in the same direction, the time taken for them to cross each other can be calculated using their relative speed. The relative speed is the difference in their speeds, which is 5 km/h. To find the crossing time, the total distance to be covered is the sum of their lengths, 350 meters, converted to kilometers. The final calculation shows that the trains will take approximately 0.07 hours, or about 4.2 minutes, to completely cross each other.