Solution:

Double or nothing

Solution:

The nail would be at the same height since trees grow at their tops.

Solution:

Because he was born before 1947(before pakistan exists) and hence is an indian citizen

Solution:

A Balloon , It was Sonal's Birthday.

Solution:

Because she wanted to see the butterfly (butter+fly)

Solution:

They all read the same rightside or upside down.

Solution:

Submarine

Solution:

In vacuum both will reach in same time.

whereas in case of air density medium it will depend on the surface area which is exposed to gravity opposing force.
gravity opposing force will increase as it is coming downwards and the amount of force is directly proportional to the area exposed to it.

Solution:

A Map

Solution:

Cold