Flight Changi Airport departs from Singapore Changi Airport at 13:10 and arrives at Ho Chi Minh City Tan Son Nhat International Airport at 14:40.
The flighttime is about 2h 30m. The distance travelled ("as the bird flies"): 405 Km. So the average speed is roughly 162 Km.
There is an 1 hour time difference between Singapore and Ho Chi Minh City