Answer
For the time of flight of the vectors: (1=2)>(3=4)
Work Step by Step
When it comes to the time of the flight, in this problem we are only concerned with the sign of the y component. Vectors 1 and 2 are both angled upwards, so naturally their launch time will be the same as vectors 3 and 4 who are angled downwards. The only difference between 1 and 2 (as well as 3 and 4) is the direction that it's being shot at. Whether it is being shot to the left or the right is irrelevant for the launch time.
