Answer:

Step-by-step explanation:
Given:
- horizontal velocity of the plane,
Trajectory of the packet is given by:
...........................(1)
...................(2)
According to given at ground level we have y = 0.
Putting this condition in eq. (2)


Now the horizontal distance travelled by the plane in the above time:
(Due to inertia of motion the packet will also travel the same distance horizontally from the point where it is dropped.)

is the horizontal distance from the target on the earth before which the packet must be released in order to reach there.