Answer: Mass on the Moon is 40 kilograms and weight will be 6.66 newtons.
Mass of the object on the moon remains the same as on Earth because mass in independent on gravity (g). Whereas, weight of the object on the moon depends on 'g' which is one sixth 'g' of Earth.
The weight of object on Earth = mass (m) × g = mg = 40g
Therefore, weight of object on Moon = m× g/6 = 40/6 = 6.66 newtons