In the Earth–Moon system, there is a point where the gravitational forces balance. This point is known as the L1 point where the L stands for Lagrange, a famous French mathematician. Assume that the mass of the Moon is 1/81

that of the Earth.
(a) At what point, on a line between the Earth and the Moon, is the gravitational force exerted on an object by the Earth exactly balanced by the gravitational force exerted on the object by the Moon? (The distance between the Earth and the Moon is 3.844*10^5 km.)
345994.5 km is correct answer.

(b) Is this point one of stable or unstable equilibrium?
Unstable is corrct answer.

(c) Calculate the ratio of the force of gravity due to the Sun, acting on an object at this point, to the force of gravity due to Earth and, separately, to the force of gravity due to the Moon.
FSun/FEarth
= ???
FSun/ FMoon
= ???

Please help me on part c.