Answer:
2.5 m/s
Step-by-step explanation:
The velocity of the package relative to the ground = the velocity of the package relative to the helicopter + the velocity of the helicopter relative to the ground
v = 0 m/s + 2.5 m/s
v = 2.5 m/s
At the moment it is released, the package is rising at 2.5 m/s.