Main airlines that flights from Singapore to Hanoi? Which one is the cheapest?

If you want to travel/business from Singapore to Hanoi, there are several options for you:

Flights from Singapore to Hanoi — Vietnam Airlines:

The national flag carrier, operates two daily flights back and forth between Singapore (SIN) and Hanoi (HAN). Flights depart from Hanoi at 10:30 and 14:00; return from Singapore at 15:50 and 19:20. The cheapest option (Saver rate) is $300 return tickets, taxes and fees included.

Flights from Singapore to Hanoi — Singapore Airlines:

The national airlines of Singapore or Singapore Airlines is among the most quality airlines in the world. There are daily flights between Singapore and Hanoi, leaving Hanoi at 9:50 and departing Singapore at 13:15. Return ticket costs between $320 (Sweet Deals) and $400 (Flexi), taxes and fees included.

Flights from Singapore to Hanoi — Tiger Airways:

Tiger Airways have mixed schedule of flights between Hanoi and Singapore and have different departing time everyday. In specific, it departs at 19:50 (Monday and Wednesday); 12:40 (Tuesday and Thursday); 21:15 (Friday); 13:00 (Saturday) and 10:50 (Sunday). Return ticket costs $200 on average and Tiger Airways offers the lowest cost for flight ticket on this route. Note that there is no meal offered on this flight.