Question 5
Question 21. A train moves from Bangkok to Chiang Mai. After 1 hour 40 minutes, another train moves from Chiang Mai to Bangkok whose speed is 5 km/h more than the first train. The trains meet each other at a station that is 300 km away from Chiang Mai. Given that the distance between Bangkok and Chiang Mai is 645 km, find the velocity of the first train.
**Editorial input convention:** Assume constant speeds and no stops before meeting. Enter the first train’s speed in km/h.
**Editorial input convention:** Assume constant speeds and no stops before meeting. Enter the first train’s speed in km/h.