Are the inertial mass and gravitational mass of a body different from each other?

Two point masses $m$ and $4m$ are separated by a distance $d$ on a line. $A$ third point mass $m_0$ is to be placed at a point on the line such that the net gravitational force on it is zero. The distance of that point from the $m$ mass is:

The distance between the centre of the moon and the earth is $D$ and the mass of the earth is $81$ times the mass of the moon. At what distance from the centre of the earth will the net gravitational force on an object be zero?

Two masses $m_1$ and $m_2$ $(m_1 < m_2)$ are released from rest from a finite distance. They start moving under their mutual gravitational attraction.

Gravitational forces operate among which of the following?

Two particles of equal mass $m$ move in a circle of radius $R$ under the action of their mutual gravitational attraction. The speed of each particle is