The mass of the woman is 25 kg because the mass is constant.
The mass of the man can be found using the formula: W = mg, where g is double Earth's gravity.
![\begin{gathered} m=(W)/(g) \\ m=(300N)/(2\cdot9.8\cdot(m)/(s^2)) \\ m=(300)/(19.6)kg \\ m\approx15.3\operatorname{kg} \end{gathered}]()
The mass of the man is 15.3 kg.
The weight of the man on Earth can be found with the same formula but using Earth's gravity.
![\begin{gathered} W=15.3\operatorname{kg}\cdot9.8\cdot(m)/(s^2) \\ W=149.94N \end{gathered}]()
The weight of the man on Earth is 149.94 N.
At last, the weight of the woman on Earth can be found using the same method before.
![\begin{gathered} W=25\operatorname{kg}\cdot9.8\cdot(m)/(s^2) \\ W=245N \end{gathered}]()
The weight of the woman on Earth is 245N.