X + y = 20 --> eqn 1
The second equation would be the mass balance shown below:
(x)(0.40) + y(0.70) = 20(0.52) --> eqn 2
Rearranging eqn 1,x = 20 - ySubstitute this to eqn 2:
(20 - y)(0.40) + y(0.70) = 20(0.52)Solve for y,y = 8 grams Finally, solve for x.x = 20 - 8 = 12 grams
Therefore, Serena needs 12 grams of the 40% solution and 8 grams of the 70% solution.
 
        
             
        
        
        
There isnt a picturee but when you add another question I will hep you the best I can :)
 
        
                    
             
        
        
        
Answer:
7
Step-by-step explanation:
that answer isnt real do u know the answer yet
 
        
             
        
        
        
Answer:
18 quarters
Step-by-step explanation: