Answer:
It is Rational.
Step-by-step explanation:
 
        
                    
             
        
        
        
First, we determine the volumes of the posts may it be cylindrical in shape or rectangular prism. 
(A) cylindrical:
                         ( π(26.7/100)² - π(24.2/100)²)*(7.5) = 0.3 m³
(B) rectangular prism:
                          (40/100)²(7.5) - (35/100)²(7.5) = 0.28125 m³
Then, we calculate for the amount of substance
 (A) cylindrical:   (0.3 m³)(2700 kg/m³) = 810 kg
 (B) rectangular prism : (0.28125 m³)(2700 kg/m³) = 759.375 kg
Then, calculate for the costs
 (A) (810 kg)($0.38/kg) = $307.8
 (B) (759.375 kg)($0.38/kg) = $288.56
Thus, the answer for A is rectangular post 
B. About $19.24 can be saved. 
        
             
        
        
        
She drunk about 
9 and 3/4 of her water
hope this helps :3
        
             
        
        
        
I think A since working backwards and looking for a pattern wouldn't help, maybe C but im not sure
        
                    
             
        
        
        
Answer:
7
Step-by-step explanation: