Given, weight on the surface of the earth, W = 600 N
Since, W = mg
where g is the acceleration due to gravity on the earth's surface 10 m/s2
So, mass m of the man = W/g = 600/10 = 60 kg
Since, mass is a fundamental quantity. Its value remains same everywhere. So, the mass of the man on moon is also equal to 60 kg.
Weight of man on moon, W' = Weight of man on earth's surface/ 6 = W/6 = 100 N