<h2>
Spring constant is 14.72 N/m</h2>
Explanation:
We have for a spring
             Force =  Spring constant x Elongation
             F = kx
Here force is weight of mass
            F = W = mg = 0.54 x 9.81 = 5.3 N
Elongation, x  = 36 cm = 0.36 m
Substituting
            F = kx
            5.3 = k x 0.36
              k = 14.72 N/m
Spring constant is 14.72 N/m
 
        
        
        
First of all, looks like your teacher is indeed pretty horrible. Secondly, the constraints to consider would be proper weight distribution, methods to minimize excessive motion of the building structure, and quantities such as volume and density, which would help in determining the optimal structure. Keeping the frequency of oscillation for a building low in case of an earthquake or natural disaster would also be a priority.
 
        
             
        
        
        
500 N  is the answer, you just tell that the moon is attracted towards the person because of the Earth's huge mass. 
        
             
        
        
        
Answer:
 I will but can you just wait for some minutes cus I am in a hurry now.
sorry that pic is a little blurry