This is about calculating the graviational force exerted by Mercury on a human and by a human on Mercury.
What approximations or simplifying assumptions must you make in these calculations?
(a) Treat Mercury as though it were a uniform-density sphere.
(b) Treat the humans as though they were points or uniform-density spheres.
(c) Ignore the effects of the Sun, which alters the gravitational force that one object exerts on another.
(d) Use the same gravitational constant in (a) and (b) despite its dependence on the size of the masses.