Precisely 84% if the Earth is made of mantle.
Weathering by water would cut its top deeper than the middle
Components connected in series are connected along a single path, so the same current flows through all of the components. If the light bulbs are connected in parallel, the currents through the light bulbs combine to form the current in the battery, while the voltage drop is across each bulb and they all glow.
Here it is given that initial speed of the package will be same as speed of the helicopter

displacement of the package as it is dropped on ground

acceleration is due to gravity

now by kinematics



by solving above equation we have

so it will take 5.2 s to reach the ground