A train moves at a speed of 35 km/h for the first 2 hours and at a speed of 50 km/h for the next 4 hours. Find the average speed of the train during the entire journey.

45 km/h

Average Speed = \(\frac{ Total \;Distance}{Total \;Time}\)

Total distance = 35 × 2 + 50 × 4

= 70 + 200 = 270 km

Total Time = 2 + 4 = 6 hours

Average speed = \(\frac{ 270}{6}\) = 45 km/h