Answer:
Step-by-step explanation:
To help us find our answer, we need to use Newton's Second law
Where F is the force (N), m is the mass (Kg) and a is the acceleration (m/s^2, on a planet this would just be the gravity)
So if we know that a person has a mass of 3Kg and weighs 30N, the acceleration (or the gravity on that planet is)
Now that we know the acceleration we can easily find the weight of the person.