Answer:
16/5
Step-by-step explanation:
 
        
             
        
        
        
Let 
Y be the age of Franco's dad.
X  Franco's age
Y = 3*X                           (1)
(Y +10) = 2*(X+10) +2            (2)
(3*X  +10) = 2*X +20 +2   
(3-2)X = 22 -10
X = 12 years old  (Franco)
Y = 3*12 = 36 years old (Franco's dad)
        
                    
             
        
        
        
The ratio is:
Chlorine : Water = 1 : 10
m ( Water ) = 15 ounces
m ( Chlorine ) = x
x : 15 = 1 : 10
10 x = 15 * 1
10 x = 15
x = 15 : 10
x = 1.5 ounces
Answer:
We need to add 1.5 ounces of Chlorine for the correct ratio.
        
             
        
        
        
Y=1.5 at the midpoint of GH. To do this you add the y values of the endpoints together and divide by two ----> 5-2= 3 ----> 3/2= 1.5
Hope this helps you !!
        
                    
             
        
        
        
Multiply by 2 which will get you a diameter and then multiply it by pi which is 3.14.