It would be the last one because 5 columns are shaded and there are 10 columns all together. 50/100= 0.5
        
                    
             
        
        
        
4,000 if you set it up as unit rate with .15 on btm
        
                    
             
        
        
        
Answer:
a = 4/27 - b/54
Step-by-step explanation:
27a+1/2b=4
Subtract 1/2 b from each side
27a+1/2b - 1/2 b=4-1/2 b
27a = 4 - 1/2 b
Divide each side by 27
27a/27 = 4/27 - 1/2 b/27
a = 4/27 - b/54
 
        
                    
             
        
        
        
Answer: 1/44
Step-by-step explanation: