Answer:
A ................................
 
        
                    
             
        
        
        
 the value of r of the geometric series n=11.3(0.8)n-1
 
General formula for nth term of any geometric series is   
Here 'r' is the common ratio
a_1 is the first term of the series
Now we compare the given formula with general formula
Compare  
  with  
The value of r= 0.8
 
        
             
        
        
        
Step-by-step explanation:
7 X + 8 = X+12 + 3X+20
3 X = 24
X= 8
m< RPQ = 8+12 = 20