Answer:
454
Step-by-step explanation:
 
        
             
        
        
        
i was incorrect unsure how to delete
 
        
             
        
        
        
Let the full marks be represented by = x
As given, 80% of x is 75
So, 

x= 
x=93.75
Hence, full marks is 93.75
We can check also-  =75
 =75
 
        
             
        
        
        
Given that the figures are similar polygons, the ratio of their ratios should be equal to the square of the ratio of their circumference. If we let x be the lateral area of the smaller cylinder then,
                        (x/210π) = (24π/60π)²
The value of x from the equation is, 
                                     x = 33.6π
Thus, the area of the smaller cylinder is equal to 33.6π mm².