Find the weight of a 80 kg man on the surface of moon? what should be hiss mass on the earth and on the moon? (ge = 9.8 m/s2 ; gm = 1.63 m/s2)

pls answer fast

Weight = (mass) x (acceleration of gravity at the place where the mass is) .

Man's mass = 80 kg

His weight on Earth = (80 kg) x (9.8 m/s²) = 784 newtons (about 176 pounds)

His weight on the Moon = (80 kg) x (1.63 m/s²) = 130.4 newtons (about  29.2 pounds)

His mass is 80 kg.  Mass is the thing about him that doesn't change. 
He has the same mass on the Earth, on the Moon, or anywhere.