Answer: I say B its a bit hard but i think i got it not  sure but Good Luck!
Step-by-step explanation:
 
        
                    
             
        
        
        
Distance = r x t ===> t=d/r
Distance (after 2 hours driving @30mil/hr) = 2 x 30 = 60 Mil
To drive same distance (60)  with r = 50, the time needed is 60/50 =1.2 hrs
        
             
        
        
        
Answer:
1/16
Step-by-step explanation:
 
        
                    
             
        
        
        
<span>let 2x be the length of rectangw where x is value of x of point on parabola width is represented as y is the length. 
  Area = 2x*y = 2x (5-x^2) = 10x -2x^3
 maximize Area by finding x value where derivative is zero
 dA/dx = 10 -6x^2 = 0
 --> x = sqrt(5/3) 
optimal dimensions: length = 2sqrt(5/3) width = 10/3</span>