The answer is B:40 hours. You take 200 divided by 20 to get 10 (the amount of 20 page sections he needs to read) and then multiply 10 by 4 (the speed he reads).
        
             
        
        
        
If the length is x+5, the width would be x(x+5)=36
        
             
        
        
        
10x10x10x10, you have to multiply 10 by 10 four times, since it's 10 to the power of 4.
 
        
        
        
Answer: The answer is 62.32
Step-by-step explanation:
See attachment